PBW isn't' cheap but seams to be the choice of the masses from what I've read. In soaking a fermenter I am using so much solvent to fill the 6 gallon container. I was thinking I would maybe make a gallon then drop another fermenter on top filling it with water to get the solution to be in contact with all the inner surface without wasting all the solution that's just sitting in the middle. Unless all that is needed. Any thoughts on this or other ideas to get the most per PBW container?