Following that period, John spent some time as an independent economic consultant before being appointed Treasury Analyst of the Australian mining and industrial conglomerate Peko-Wallsend Ltd, then amongst Australia's largest fifteen public companies. In that capacity, he was closely involved with the centralisation of the Peko-Wallsend Group's domestic and offshore treasury management. This entailed establishing centralised domestic and international cash management functions together with the formulation and implementation of a foreign exchange exposure management system. He was also responsible for the Group's international banking and foreign exchange exposure management.

Concurrent with his time at Peko-Wallsend, John was a member of the Economics Committee of the Australian Mining Industry Council.

John Rush joined the Bank of America majority owned merchant bank BA Australia Ltd in Sydney in 1982. As a Senior Manager in BA Australia's Financial Markets Advisory Group, his primary responsibility was for the presentation and development of that company's Foreign Exchange Workshop. In this role over a four year period, he conducted workshops for over seven hundred participants in Australia, New Zealand, South East Asia and the United States.

Since undertaking independent treasury management consulting from 1986, John Rush has established a formal relationship with the then KPMG Peat Marwick as a treasury management consultant and has provided advice as a recognised foreign exchange expert to the legal profession in both Australia and New Zealand in cases requiring foreign exchange expertise, giving expert evidence in Court proceedings when required. His evidentiary work in a particular case has been reviewed by the Privy Council in London. Leading New Zealand Queen's Counsel James Farmer QC said of a Rush tailored foreign exchange workshop for lawyers:

John Rush's seminar presentation explaining the principles of foreign exchange transactions was extremely helpful to me in a situation where I was having to prepare for litigation involving such transactions in a complex context. His approach was consistently authoritative, lucid and patient.

As Financial Training Consultant to the Securities Institute of Australia, John was responsible for the design, development and updating of Securities Institute Education Financial Training courses. John has also been invited by the Securities Institute to make about one hundred presentations and lectures on various aspects of financial markets functioning and the management of financial risk. He is also a course presenter for CPA Australia (formerly the Australian Society of Certified Practising Accountants) and a technical contributor to the New York publication International Treasurer. In his work in New Zealand, John has presented foreign exchange workshops for the Reserve Bank of New Zealand and has been a course presenter for the New Zealand Institute of Chartered Accountants.

Other affiliations derive from John's being a recognised technical assistance expert with the Monetary and Financial Systems Department of the International Monetary Fund in Washington DC and a consultant to the Asian Development Bank in Manila. He is also a member of the Professional Risk Managers’ International Association (PRMIA).

At the beginning of 1995, John Rush joined the Oakbridge Group as Principal Consultant. Having joined a group dedicated to the provision of professional financial markets consulting and training programs, he is able to provide a perspective from the vantage point of one who has been a central bank economist, a corporate treasurer and has been closely linked with a leading international financial markets trading operation. Above all, he has been widely acclaimed for his technical knowledge of financial markets and a presentational style that encourages the relaxed, active participation of workshop attendees. His other strengths lie in verbal, written and presentation skills that clarify technical concepts and practices often confused by jargon and mystique.

In 2002, John Rush joined three other experienced risk management professionals to form The Kennington Alliance (TKA), a specialist risk management consultancy directed by highly experienced consultants who possess complementary skills in financial, systems and marketing risk management. TKA is able to develop strategies that will give clients greater certainty, increased profits and lower costs in their future business dealings. John's contribution to TKA's accumulated expertise lies in his ability to engineer innovative solutions to otherwise intractable financial risk management problems, thereby providing clients with certainty that did not previously exist.

John is noted for explaining to, and interpreting for, financial institutions and corporations those economic policy decisions of governments and central banks which affect economies in general and financial markets in particular. This expertise is borne out by the comment of Ian Hawthorn (then Financial Services Partner of Price Waterhouse in Sydney) who remarked:

A particular gift is required to present the complexities of financial markets clearly and understandably. John Rush certainly has it. Participants in his workshops have commented to me that their clarity and usefulness exceeded anything they recalled from their university training.

That opinion was reinforced by Professor Peter B Dixon (Director of the Centre of Policy Studies at Monash University in Melbourne, Australia) saying:

John Rush's ability to explain in clear, succinct, practical terms the principles by which international financial markets function is impressive.

John is also an experienced consultant in Asia, where his presentation skills and technical knowledge continue to produce excellent results. For example, Teddy Lin (Vice President and Country Treasurer of Bank of America in Taipei) said of John's consulting:

John Rush was invited to conduct foreign exchange workshops for groups of our corporate clients. The presentations were very successful, in that they both imparted practical technical knowledge and strengthened our client relationships. John was an excellent communicator of technical financial material to workshop participants whose first language was not English.

Another view expressed of John's work in Asia was by Tom Huse (then Vice President, Training Services of Bank of America in San Francisco) who stated:

John's workshop presentation style, while always authoritative, encourages questioning and interaction amongst participants. His techniques also remain highly effective in a non-Western cultural environment.