This darn 1990 P60 van I'm working on:

I pulled the tank again because a rubber line kinked, and the sending unit is still flakey.

This time I completely drained it, and it has a layer of sludge in the bottom.

What are some alternatives for cleaning? I know the subject has come up before, but a quick search revealed nothing. I was going to pressure wash it, but it has baffles, and I'd only get the middle clean.

Thanks.