I do mine a six pack at a time whenever I get a some used bottles. I fill my kitchen sink with hot water, then add about a quarter cup of Arm and Hammer's Super Washing Soda. This is cheaper than oxyclean, and removes labels in 20 minutes and really gets the adhesive off as well. A light once over with the sponge and running water, a quick rinse and they head to the bottle tree to dry until I'm ready to sanitize and bottle. The only thing I've found that is a huge pain is getting the foil off of beer bottles like Negra Modelo. Any tips on removing that foil easily would be appreciated.