Metal Rescue.

[Ranger]

BB's don't do crap, they just roll over the rust.

Thats why I said with washers, big ones at that. Most of them I put on the ends of bolts with a nut and it did a great job. Think of it as a scraper with bearings


And yes, I shook the tank every few hours before I flipped it. What I did was start with the top of the tank, then the sides, then the bottom since I wanted to get all the crap to sit at the base.

Fill it with heavy yet small rough objects that are metallic and shake.

[Ranger]

Totally missed it, but thats a really decent job it did. 2 days would have been just right..i agree!! and its not environmentally harmfull flush crap down the toilet when done

Most of the rust removing stuff is non toxic. I did mine on my grass and a little leaked out and did nothing to my lawn.