Theoretically you can wiggle your way out of this if the course is part-time and not the main objective of your stay in the US.
To do a private certificate, IR or multi, you would need to go through the TSA process which require visa details. So while in theory a part time can get you under the wire as far as a visa is concerned it wont with the TSA.
Moral is dont play fast and loose with the rules, get the visa, do the TSA and go fly.