Depends. Vinegar will eat away the rust. I had a plomb wrench I did that too and you can see the micropitting inside the pitted parts so it worked great. I would guess it depends on how rusty your vise is and if you are willing to neutralize the acid after with baking soda in all the nooks and crannys.
If you use vinegar, there are lots of tutorials online.
I'm huge fan of Evaporust but it can be pricey for large objects. I use electrolytic rust removal for the big stuff. You've got to get primer or some kind of rust prohibitor on the metal pretty quick after removal or you'll get flash rust.
Don't put cast steel in vinegar. It will eat it. I have a vat of vinegar for soaking steel parts. Put a brake drum in just to see what would happen. Ate it, did serious damage