Do not know what brand anaerobic you have to remove but Permatex makes a remover for their anaerobic products.https://www.permatex.com/products/gaske ... c-formula/
I have heard where paint remover works well to remove the anaerobic, never tried it.
If removing the anaerobic from split crankcase design engines (ex Merc Mark 30, Mark 55, Merc 200, etc) that have accurate machined mating surfaces then they are put together (without sealant) and line bored for the crankshaft/ reed cages/bearings/etc to very close tolerance as a matched set you need to be careful to not damage those 2 mating sealing surfaces. Also if resealing these split case engines the mating surfaces need to fit nearly perfect then it only takes a very very thin layer of the anaerobic to do the job. I always check the flatness of the split crankcase mating surfaces and correct any highs before sealing with a very thin dappled coat of anaerobic. My applications of anaerobic on split crankcase engines are so thin that to remove sealant is not an issue with a careful draw scrape with a razor blade.