I've got a Pils in secondary lagering right now and I saved a pint jar of the yeast, trub and all and stuck it in the fridge. (Wyeast 2000) I've done yeast washing before, but I really did not have the time. I sanitized the jar in the oven for an hour at 350 and the lid with Starsan.
I want to brew a batch of Schwarzbier when I get home. When I have the chance to brew next, it will have been in the fridge about 3 weeks.