I've used them, but get better and more even results with one of the ammonia-based polishes like Flitz, Simichrome, Maas, etc. My favorite is Mother's Mag, available at auto stores. If you really want to work it, you can apply it with a wine cork.
Depending on where and how bad the rust is, steel wool with Ballistol or WD40 works too.
Another great variant on a rust eraser is bunching up a shop rag and using it to wipe stone slurry off a J-nat. Once it gets impregnated with the slurry, it's a great rust remover/polisher.