DS1 was the same. We just had to stand him in the bath with one of those shower heads attached to the taps. He would control the shower head/water & we would wash him. Hair we would give him a wash cloth to hold to his eyes and quickly rinse with the shower head.

He grew out of it just before he turned 4. He now swims & loves the bath. Still not so keen on the shower except at swimming & hair washing can be painful at times for us all.

Don't know if I have helped. Hopefully in some way x