Cleaning out gas tank 1958 Ranchero

[Pamlico]

I recently discovered I got water in my gas tank thanks to Hurricane Florence. Rust showed up in the see-thru fuel filter. I drained the gas and a lot of rust particles came out. I can pull the tank and go through the process of cleaning it out as usual. The problem is, on this tank, the pickup in the tank has a "sock" around it and is not easily accessible. I don't want to be so aggressive as to ruin the sock around the pickup. This tank is about 12 years old. Any ideas?