I frequently use my needle files on plastic, and also on filler. In either case, but especially the latter, the file clogs up rapidly. Right now I use a dremel wire brush to clean it, usually just holding the shank and drawing it across the file manually. Sometimes I chuck it and run the tool, but I am afraid of dulling the teeth if I do that very much.
How do folks clean their needle files? Is there any solvent that will dissolve the gunk without leaving deposits on file?