I use Orvus a livestock wash. It's great for soaking stains out of old quilt tops or washing quilts. I use color catchers also, look how much this color catcher absorbed from a recent quilt soaking. The top turned out great too!
As far as I know, I am the only remaining living descendant from my Great Grandmother and Grandmother Crutchfield that still quilts. I am fortunate enough to have inherited two of their quilts for my collection.