Howdy - I'm starting to re-gasket an old Vigilant and for the life of me I can't clear out the channels of old cement completely. Wire brush then wire wheel on my drill and the dust flies like crazy but obvious patches of uneven old cement remain. The arthritic hands don't help...is there any chemo or technique anyone knows of? Thanks in advance for any suggestions. I've gasketed other stoves but none with this kind of buildup.