Fuel tank cleaning EA82T

Well, I pulled the tank on my 87 GL-10 that's been sitting for around 11 years, and the fuel was a disgusting mess. It looked like a crosse between maple syrup and road tar on the level float. Most of the fuel didn't look that bad, but it has a nasty layer of varnish and other gummy residue inside it. I was looking at acids and things to clean it, but I was concerned about the pickup and any filters that might be inside it. I can't really see what it has inside, but I assume it must have a pickup in the bottom of the tank feeding the line on the front. It would barely flow anything out of the line to the pump. Has anyone ever tried cleaning one before? I'm going to see what I can do with this one, but I'm thinking I might have to replace the tank.