DS has a ton of hair. He's had it since birth and we had no issues washing it when he was in an inclined infant tub. But since we moved to the big tub, we've gone through several phases of him hating the rinsing part of bath time. A month ago we switched to using the shower head instead of pouring cups of water and it's usually gone over well. He just closes his eyes and rubs them sometimes.

I think swim class has helped too, but it's still his least fave part of bath time.