I've been cleaning and scraping the old crankcase sealant the
PO had used on the crankcase for 2 days now and still have a lot of work needed to totally remove the residual sealant. What methods do you guys employ to get this hard and brittle sealant residue off the matting surfaces? Any suggestions, tips, directions, or comments is highly appreciated.

Almost every conceivable mating surfaces around the crankcase perimeter were covered by this dark brown sealant and I'm patiently trying to remove the residue. And it's taking too much time to get this done this way. Thanks.
Tony