Wow that's seems like it takes some time.I just spray in some de-greaser shake it about.With tap and fuel cap on.Then rinse out with water until water becomes clear.Then depending on whether I need the tank I either blow it out with air gun or sit it in the sun.I guess if you don't have a compressor then I'd properly still use de-greaser but I'd have to find some brush or brushes to go inside and wash it like that.I don't use metho as Mr Davis said as if it has a lot of oil (Say in a 2 stroke application) metho really isn't the best a moving the build up gunk around and generally still hangs around.He'd properly get the same result with water and the small rocks.
