I eventually bought all my bottles then I didn't need to get the labels off and they are all the same size - much easier for capping. I rinse with hot water and a tiny drop of dish detergent immediately after pouring. Then I wait until my wife nags me about all the bottles in the dishrack and put them in the box they came in until I'm ready to bottle again.
I have a FastWash 24 with a second rack. I also got a plastic storage tub from Target and drilled a 1-inch hole in the bottom corner for easy drainage (use a rubber stopper when necessary). I do it in the utility sink in my basement; I imagine a bathtub would work as well. I put a rack of bottles in, wash with PBW for 5 minutes, put the other rack in, wash for 5 minutes. Drain the tub and rinse it good, put a rack in and rinse with clear water, same with second rack. Drain, then fill again with IoStar solution (need to use a low sudsing sanitizer) then run each rack for 5 minutes. The whole process takes about a half hour and much of the time I can putter around doing other things. It may not be cheap, but it's waayyy better than washing each bottle individually!