Any military-grade coffee that is still hot can be used to strip the top layers of wax off linoleum. Dump the pot where the old wax is thickest and mop up.
Boiling hot coffee poured into the action of a firearm will wash away grit, sand and dust that is trapped by the grease and oils.
Grounds that are still wet can be used as sweeping compound and will gather up grit, hair, and dust if spread liberally and then swept up.
Dried grounds used in a sandblaster will remove tarnish and polish soft metals. Saturated with wood glue dry coffee grounds makes a useful filler.