Well, I used the POR-15 tank cleaning kit today. I rinsed the tank out well first and tried to flush as much of the loose stuff out as possible. I then set up a sling to hang the tank from. This allowed me to move and flip the tank to try to get all internal surfaces with the cleaner, prep, and sealer. I used a lot of hot water to rinse, then dried it thoroughly with a hair drier. A little time consuming, but the areas that I could see with a flashlight got really clean looking, and seemed to be well coated with the sealer. Takes 4 days for the sealer to cure, and hopefully my new pads, straps, etc., will be in soon. Anxious to get it back on the road!