[hharney]

Ernie
The tube is not that long. Maybe 12 inches. The tube passes through the tank out the bottom so only as deep as the tank or wing. The idea that Jim suggested will work. Add the water from the fuel service cap and allow the water to soften the contaminate. Then use the zip tie, wire, plastic weed whipper line or similar to push the junk loose. Flush with water or stoodard solvent (mineral spirits). You may want to make up some plugs with flags to keep the critters from going up into the tube.

Drano is very corrosive to aluminum. I don't think it would help anymore than water either. Remember folks to practice checking the free flow of these drains when servicing with fuel. Make sure you see the fuel visually drain out the bottom of the wing. If you have any doubts check it out. If the tube corrodes because of plugs the water from the top of your wing will find it's way into your fuel tank. This has caused a crash of one Skymaster that I know of. Luckly they all are still alive.