Vicki,
Use it in your bath then!
I thought they were talking about the stuff that is a laundry additive, keeps the soap scum out of your clothes, I have to use it here to help keep the rust out of the clothes. I use a rust stopper salt in the water conditioner thingy in the basement, but the Calgon or whatever that stuff is that I have used, helps keep the whites just a bit whiter, just a bit longer.
I would guess that if you fed the bath stuff to your holding tanks they would sigh AHHHHHHH (ain't that what the commercial says???
)
Carol