Rust - Rust proofing frames, Rusting treatment and prevention

drill a 5mm hole in the bottom of the bottom bracket, and when ever you change the b/b squirt a load of wd40 in there, you can get stuff called Framesaver, which does a good job, but not sure where from.
recently tried to search for it....no joy.

It's tough to find but a place called Ceeway sell it.