You can put the BBs in the tank and put in in your dryer (with heat off) and tumble it. wrap it in a blanket to pack it so it does not bounce around in the dryer. Reposition the tank a few times to change cleaning pattern. I know it sounds dum however I have done it with good results. Then buy a "Creame Kit" and coat the tank to prevent it from rusting again. The kit comes with cleaner, acid for etching and the Cream coating. If the directions are followed it works well. If not the coating will peal off. Be careful you dont get the cream on the screens. If you do take the air compresser and force it out of the screen from the pickup tubes at the petcock.
