Okay, thanks for the responses! I think what I am going to do is do the HP spray first, let it sit overnight to let it evap, then boil it (if I can get my hands on a big enough pot and burner, because I feel a garbage can is way too big), then do the solarizing method with a white garbage bag because that is the closest I can think of, and then do the salt treatment for 2-3 weeks, and then let it sit in water for however much longer it takes to sink. This came out of the Muddy Mo so I'm not taking any chances.
Mistergreen: how often would you change the water and salt on that salt treatment? and also what kind of salt would you use?
And also, once you get a piece of DW waterlogged and sunk, how long does it retain that quality?