I realize I'm chiming in somewhat late in the game
, but I'd like to share some insight:
1. If your tank is made of polypropylene, you will need to replace the tank. Polypropylene will absorb the smell and will not let go of it. If you come across a chemical that works, you will be the first...because it doesn't exist. If you have a stainless steel
tank, you're in luck. Use any degreaser with dispersant properties, rinse the tank several times, use soap to wash the degreaser residue, rinse again, and you will hopefully have a clean tank.
2. If you have not run the Diesel laden water through your plumbing
fixtures, you have saved yourself a lot of money
and labor -- as having done so would require you to replace the water lines, fixture, and pump (if you have a pressurized system).
Best of luck! While it is a mistake, consider it an opportunity to revisit the procedures you use for refueling. Perhaps use a clearly labeled deckfill cap for both tanks
and make sure the Diesel tank requires a deck
key. My boat's configuration makes it impossible for such an error to occur -- as I have installed a completely different filling system for fresh water not only to make it easier but to make it impossible to confuse it with the fuel