I use erasers at times to remove case colors & sometimes bluing around inlays or cut figures for a grey tone effect.
Go easy with them. They are abrasive. Some more than others. Finding out how much more could be disheartening.
They do an excellent job brightening up inlays but again be careful of the surrounding metal finish.
Even the softest of them can pick up a speck of hard material or dirt while cleaning and a few swipes of it accross the surface will leave you with some never before seen scratches in the blue or C/C.
Cleaning engraving of old dried oil, finish and grime takes some time and careful techniques if you're determined to preserve the remaining finish and/or patina.
It's not a scrub and rinse type of operation.
