[danShumway]

My Twisbi has never dried out, so I'm not sure. I clean it maybe every 3-4 months with cold tap water, usually whenever I want to switch colors. My rough understanding is that Noodler's ink becomes permanent because of a reaction with the cellulose in the paper -- it shouldn't have the same reaction to metals or plastics. I'm not super-up-to-date with the mechanics, so don't quote me on that. But regardless, I've never had any difficulty getting residue out of the pen.

Certainly if you spill it on your clothes, there is probably nothing reasonable you can do to ever get rid of that stain. Presumably that's the desired effect from a waterproof ink anyway though -- you don't want it to be removable.