as far as using our washer and detergent....I'm not terribly concerned about foam. We bought one of those high efficiency washer/dryer sets that uses less water and electric than normal....I use about a shot glass of soap for a "normal" load of jeans, shirts, etc, and I cut that amount in about half for the suits and towels that get used by the tub...also I add an extra rinse cycle, just to clean things up a bit more.
I did notice, however, after my friend showed up (it was her, me and my son), the tub WAS relatively foamy....I attribute that to the "normal" wash cycle and soap amount...