I don't have the balls to let my whole mash sour, however, I just mashed a pound of pilsener on my stove. Going to pitch some whole kernels in it and see what happens in a couple days. If it's real nasty, I won't use it. But if it sours up and has a little funkiness, it's going in with the main mash when I brew later this week.
I'm also going to make a big starter of Wyeast 3724, then pitch a smidge of the wyeast 3711. That's what the Odanata guys do, and they get their Saisons to ferment really dry, even with no sugar.