Orrrrr you could teach your son to take a bath and use a condom instead of cutting buts off him.
ORRRRR you could wait until he is twelve, and say "Hey son, here are some fantastic articles about your penis. I want to take you to the hospital and have bits cut off it. How do you feel about that?"
And then, if you have given him the truly fantastic articles that you sy you have seen, that completely refute everything I have pulled of Google, he should agree with you right? And will happily get in the car to have pieces of skin cut off his penis.
If it is such a very important thing to have done, why on earth would he refuse, gievn a choice?
Or perhaps you feel he would refuse? Perhaps you can't produce such empirical evidence that would convince anyone to have pieces cut off their penis? Perhaps you are worried that if you give him a choice, he will choose not to?
Perhaps it's not as important as you have always thought, if a rational twelve year old would choose not to ... of course, if he DOES choose to, you could be happy in the knowledge that he had a choice and you got your own way. You can pat yourself on the back.
If you do it now, and he gets to twelve, or 20, or 45, and says to you "Why did you cut pieces of me off? What the Hell is wrong with you that I wasn't perfect enough for you?" - what are you going to say then?