Tbh I think this is just another form of avoidance. You do these crazy things to humiliate yourself because it would be more painful for you to be a real person interacting with real people in a real way. You do this instead of doing what you fear.
"I'll do this crazy thing and when nobody reacts I'll realize that it's fine to just be myself." Except this crazy thing that you're doing is not an authentic expression of yourself. It's just the mirror image of your anxiety. Your real self is still safely tucked away behind your crazy antics. And you know that, which is why you can get yourself to do these crazy things but you can't get yourself to do something normal, like smile and say hello to a stranger. You can always think: "Well, who cares if they had a bad reaction? That's not the real me anyway. That's was just me humiliating myself, so their opinion doesn't really matter." But it does still matter, otherwise you would stop doing crazy things and just be real.
Being a real person is much much harder than humiliating yourself in public. Maybe this kind of thing helps some people, but I suspect you could spend the rest of your life acting like a maniac and never overcome your fear of the opinions of others. Acting strange isn't loving yourself, it's concealing yourself and protecting it from harm.
I think the real solution is to love yourself no matter what. Every time you screw up, every time you fail, every time you embarrass yourself, every time someone gives you a dirty look, every time someone rejects you, tell yourself it's okay. It's okay to be a person who screws up, fails, does embarrassing things, isn't liked, and gets rejected. You don't have to be perfect. No one has to be perfect. Isn't that the goal of all this public humiliation? To convince yourself that it's okay to screw up? So why not skip the antics and just start giving yourself that permission?
If you're doing this to prove that other people aren't going to freak out just because you're acting like a weirdo, you're still making it all about other people's opinions. You're still making it all about the other person's tolerance and acceptance. And it seems to me that that's the whole problem. The problem is that you have no tolerance or acceptance for yourself. You make your self-worth, your freedom to be yourself, depend on other people's opinion. When other people give you permission by not reacting, then you give yourself permission. You still need reassurance from other people that it's okay to be you. And I don't think this kind of exposure therapy is necessarily going to give you that. Maybe it will, maybe it won't.
What you have to learn is that no one else can give you that reassurance. It has to come from yourself. You have to forgive yourself for being who you are. And when you do that, you can start getting better.
I love Society. It is entirely composed now of beautiful idiots and brilliant lunatics. Just what Society should be.