hmm.. if you cant flame the wire, there's always the molten caustic soda method, but thats pretty dangerous - take some sodium hydroxide (powder) and mix it 4:1 with some non-iodized table salt, then melt it with a torch, then insert the wire you want stripped into the molten soda mixture for 1-5 seconds, then quench in water.

If you have a laser cutter, you could experiment with the strength needed to just burn off the insulation without melting the wire. - There are special machines that do this, and can supposedly strip higher than 50 gauge wire without damaging the wire.