This is a very dangerous area. Don't 'trust' anyone - talk to the US Embassy and establish *exactly* what you need. Remember that if your name gets onto the INS computer as a non-desirable you will never, ever, get into the US again. The same applies to instructors going to the various schools offering JAA training.
A very good friend of mine spent 48 hours in the chokey at MCO before being deported and has just had to explain to his kids why he can't take them to DisneyWorld!