The toilet is what I use. I also am careful to use a citric acid cleaner, as it chelates the small amount of lead present and renders it less toxic. Probably not perfect, but I feel better about it.
I actually tumble in citric acid alone for about half the time, then I pour most of the water out (not enough to lose pins), add soap flakes and top the water back up. The soap is alkaline, so I don't trust the citric acid to work very well in combination with soap. I just let it get the oxide off the brass and the lead compounds out of the solution before neutralizing it with soap. I'll have to get my old pH meter out to see what is actually happening in this regard.