I had no free buckets to hold the derusting solution in that the vise would fit comfortably, so I had to use a plastic box that was too wide. It would not submerge fully in the 1 Liter of derusting solution I bought, I had to soak one side for 24 hours and then the other side for 24 hours. It mostly cleared the rust. I’m considering painting it now, but I don’t think I’m going to.
Your mistake was buying derusting solution. Just use vinegar with some salt.
Either way, if you don’t paint it, atleast make sure to oil it afterwards, otherwise it will rust again immediately.
I’ve been using vinegar for this for most of my life but have never added salt. Does that speed it up, or help in some other way?
I don’t actually know if it helps at all. Vinegar on its own also seems to work.