I found myself in a similar situation, with my favorite of 4 chicks turning out to be male. The first time I tried putting on the No-crow collar it was a disaster. But I waited a few days, and tried again just at bedtime. I put it on loosely, but tight enough that it would stay on, then tightened it up about 2 days later.
He is wearing it without issues, and it is making his crowing softer. He still crows and makes all the other chicken noises, just not as loudly. He also engages in all his other normal activities, though it took about a day. When I put the collar on at bedtime, I also held him for a long time then let him roam around a little before setting him in the coop, to make sure he was reasonably comfortable and safe.
It could be worth a second shot at the collar if you're still struggling with re-homing.