My Dad, 85 & some dementia, will not take a bath. He says he wets & wipes. Help?

I know we are use to the finer things in life like bath tubs and shower but now they make hot wet ones (medical ones) and a spray bottle (warm water) with shower gelin it that can be used or you can place a chair in the bath tub with the extendable shower head so he can use directly. This will give him control over the water and spray nozzle. I know it is extra work but it you can swing it, please try.

Ask why he is not taking a bath. Is it fear of drowning, slipping ?
It may be fear or that he does not want a helper.
Tell him he smells bad and that he cannot go out or around others with this going on. He may be ashamed of smelling bad.