Potty training a very reluctant 3 year old

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My youngest children (of 6) are 3 year old twins, one boy, one girl. They turned 3 at the very end of July. My little girl has taken well to potty training. She's usually accident free and doesn't often need to be reminded to use the toilet. She uses a pull up at night, but it's getting better. She can make it through nap time (about 2 hours usually) and stay dry. She has transitioned from using a potty chair to sitting on the toilet (with the adapter). Her twin brother, however is another story entirely. He won't even let me put underwear on him, let alone have him sit on the potty chair. When I try to put undies on him, he screams bloody murder "no undies! no undies! need diapers!" Once I get the undies on (if I can) he runs away, takes them off, shoves them behind some piece of furniture, and brings me a diaper while saying "need diapers". Biologically, he's pretty ready to potty train. He can stay dry for long periods. He takes off his diaper (or tries to, we really try to catch him while he's doing it) when it's wet or messy, especially when it's messy. He can dress and undress himself (he does it often during the day). We're just butting heads with his absolute stubborness and refusal to even give it a try. What should we do? I really don't want to resort to bribery, but if this continues like this, I might have to. Do sticker charts REALLY work? What tips and tricks have you tried with a really stubborn kid that have worked?