>I realise that these temp files will be deleted when VFP quits, but my app generates some huge temp files (over 100 MB) and if a user runs say 10 reports it creates 1 GByte of test data in the same VFP session which is not desireable

If these temp files are from a SQL cursor, then if you do a USE IN SqlCursor, they will go away when you are done with them.

SELECT * FROM blah INTO CURSOR testdata
* do whatever you need to do with testdata here
USE IN testdata