like Texas figured out. The coach could start a charity and fund it with his own money. The charity could then pay NIL money to players for the use of their name/image. Other donors could also contribute to the charity.
Not too different from Frank Howard's idea of starting IPTAY, except it's all legal now. While IPTAY should have (and probably was) all above the table, the same boosters who contributed to it had other ways to help get players. Other than during the time of Danny Ford and B.C. Inabinet, I don't know if much money was paid under the table by our boosters, but I suspect it was certainly some. I ate in the training dining room daily in the '60s and learned if anybody needed some cash, you could go pick up trash in and around the stadium and get $20 or so most anytime. I have always wondered where that money originated.
I never tried to make spending money that way - found it more fun to play in a band and get paid better.