I've collected a large mixture of shuriken through polypiling. The different enchantments and BUCs are easy enough to mitigate for stacking, but I have quite a few that are poisoned (of differing ench/BUC). None are rustproof yet (that's one reason I want to stack). Besides using and waiting for it to wear away, dipping/rusting, or poisoning all of them, how can poison be removed? Will Cancellation work?