I don't think booting a horse in the belly is going to teach patience. Scratch that - I KNOW it won't.
As for young, I only start young unhandled stud colts, nothing else anymore and they ahave NO handling and yet in a day or two I expect, no demand they stand quiet and unmoving in cross ties.
And as for KNOWING it won't?? Have you tried it?? Unless you have you don't really KNOW.
There are no bad horses just bad handlers.