I have tried a number of different cleaning solutions. Industrial strength degreaser mixed with boiling water, TSP and boiling water. TSP-PF and boiling water, Cascade dish detergent and boiling water. I also bought 5 gallons of Evaporust and tumbled that for 24 hrs. The best cheapest solution so far was 2 cups Cascade, 1 cup TSP and 5 gal boiling water. The Cascade has sodium silicate in it as a corosion inhibitor and prevents flash rusting while tumbling. So after 5 days of cleaning the tank is looking good.
