My philosophy on the birth tub: I just went through labor and pushed out a baby. I am now recovering from birth, breastfeeding a newborn, experiencing cramping as my uterus returns to a somewhat normal size. My husband can deal with the tub. I don't know how he did it, nor do I care! Let him figure it out ;)
I think breathing through pushing is really important, and doing your own perineal support. Listen to what your body tells you.