First off, I hope when you say "toss the Williams" you mean toss it into the shower and use it as a bath soap. It works pretty good for that, and why throw anything away? (I'm cheap like that)

Secondly, "Softened" water is not the same thing as "Soft" water. I know there will be some that argue, but many people who deal with water softeners will complain about soaps not lathering, and not rinsing clean.

I will agree that buying bottled water just to use a cheaper soap seems counter productive. Just use a soap that works with your water. I may be cheap, but I'm also practical <----- Not filled with Williams