If there's someone local might be interesting to either get a quote on Dry Ice blasting or see what's involved in renting the stuff necessary. Never done it personally, but it looks like it works good
http://www.canadiantire.ca/AST/browse/6/Tools/ToolStorage/MastercraftMechanicsToolChests/PRDOVR~0580896P/Mastercraft%252BMaximum%252BTool%252BCabinet%25252C%252B56-In.jsp
There ya go