Rust removal, how far????

I had a VW once that had a hood with rust spots all over it. Looked like maybe it had been towed behind a motorhome or something. Pitted & rusted pretty bad (but no holes all of the way through). I used some Duro Extend (I think that's the name. Paul Harvey used to advertise it) to kill the rust. About a year or so later I used paint stripper on the hood. The pits were still there of course, but all of the rust was gone. Just used spot putty on it & never had a problem.