If you ever accidentally put too much soap in your washer and it starts to bubble over, just add some vinegar to the wash. It cuts down on the bubbles. This is a tip learned at my local laundromat. When a kid put a ton of soap in one of the washers.
It's also good to put down your kitchen sink every so often.
I use it or lemon juice as a final rinse on my hair, to be sure I've gotten all the soap out.