sitz bath question

hi MH, I once did attempt yr sitz bath with no success. The problem is that water is horrible here, a lot of chlorine and God knows what else, so I cannot really stand the whole 45 min into the bathtub, I already have a very dry skin and after about 20 mins I start feeling like the water was corroding me.
Do you think the time could be shortened? I live here and this is the only water I can use.
thanks.