There is no way my dog would follow me into the tub, she hates water! I tried swimming with her, she's very attached to me and I thought if I waded in and called her, she'd jump in. Nope! She cried and cried but would not go in.
I found using warm water made it better, before all I had was the outside hose and the water was cool. I have a non-slip mat in the tub and use the handshower. She doesn't fight nearly as much as she used to, but usually whines while I do it. I just try to be quick! lol She has gotten better, but she will never love it. She doesn't have to, she just has to tolerate it.
If you do think he might bite, then be safe and get him used to a muzzle so you can use it at bath time.