A good way to tell the potential customer you don’t teach while performing is:
“If you hire a singer for an event – the singer doesn’t give singing lessons at that time. Cher just performs but she doesn’t teach. Singing lessons, Piano lessons etc, are usually taught step by step AND The things I’ll be bringing are not that easy top learn. Students should start at the beginning, which isn’t part of the show I do, or any other magician either that I know of.