Just thinking out loud here, and I'm not trying to start another water v. petroleum battle. On a few cleanup jobs I have had excellent results using one Finish brand automatic dishwasher detergent packet dissolved in water to make a concentrated cleaning solution. I wonder if it would work well to cleanup bp guns. I don't want to risk damaging my guns to find out, but if someone has a junker and feels like experimenting, that would be interesting. Anyone?