There are products that seem to be equivalent to Framesaver, two I have on hand are LPS 3 and PB 'Corrosion Stop.' Both come out as a waxy substance, very thin at first but it thickens as it dries.

Some years back a C&V contributor was conducting a test of various rust preventative materials, but he dropped out of sight before showing his results.

I just did a thorough de-rusting of the internals of a frame with an oxalic acid bath; I know I didn't get every bit of the rust but with it covered with this stuff (and I used a lot) am pretty confident nothing further will happen.