It ain't that easy. Strapped the tank to the wheel of the H. I put in 3' of chain, a handfull of drywall screws, and
some nuts, and a qt. of acetone. It tumbled for 3 hours. Next 3 rinses of Dawn, Purple Power, and hot water. The drain water was reasonably clear but a magnet still brought up crud from the bottom. I cut the tank at the seam so it could be sand blasted. There was still enough crud that it had to be scraped out. Next time I'll skip the cleaning part and just go for the cut-off saw.