Hmm... Sounds like a bad idea to me. There are some small inner workings around the trigger area that are tough to get to. I would think that you would risk it either not drying completely, or worse, having some soap residue build up inside. (I have heard reports of stainless steel rusting, despite the name.) I have the M&P 9. I just use an old toothbrush sprayed with solvent to scrub the frame and chassis.

Good luck.

Get some "Gunscrubber"(Polymer Safe-Silver Cap) and it will clean without harming the polymer frame. I use it on my M&P9 all of the time. You must lubricate your firearm after using it because it removes everything and leaves a dry as a bone surface.

Thanks for the info. I researched the "Gunscrubber"(Polymer Safe-Silver Cap) and it sounds like pretty good stuff, although before the polymer safe formula was available, I read where some marred their bodies or grips with the original stuff. I still am curious if anyone has ever submerged their polymer chassis in a mild soapy soak and scrubbed the action with a nylon brush to clean it. Knowing the materials involved in the chassis makeup, I'm still intrigued by the idea this isn't necessarily a no-no, provided you're very diligent in the drying step using compressed shop air and leaving the pistol unassembled for a period of time for an extra measure of certainty that it is throughly dry, and then of course a thorough oiling/lube for the trigger action area. Having said that, I can't quiet bring myself to do this as of yet

Originally Posted by supra001

Thanks for the info. I researched the "Gunscrubber"(Polymer Safe-Silver Cap) and it sounds like pretty good stuff, although before the polymer safe formula was available, I read where some marred their bodies or grips with the original stuff. I still am curious if anyone has ever submerged their polymer chassis in a mild soapy soak and scrubbed the action with a nylon brush to clean it. Knowing the materials involved in the chassis makeup, I'm still intrigued by the idea this isn't necessarily a no-no, provided you're very diligent in the drying step using compressed shop air and leaving the pistol unassembled for a period of time for an extra measure of certainty that it is throughly dry, and then of course a thorough oiling/lube for the trigger action area. Having said that, I can't quiet bring myself to do this as of yet

No offense, but I think you might be a little too worried about so thouroughly cleaning it. I like to keep my gun clean as much as anyone, but the M&P was designed to be a tough, duty pistol. Meaning, it can run for quite awhile, clean or dirty. I just scrub all the metal parts with a brush (with solvent), wipe it away with a rag (using a rubber-tipped dental pick to get into the tight areas), clean the bore, then put a drop of oil in the 7 places the manual states. I do this after every range session and it's stayed quite clean and has never failed (aside from a problem I had with the mag catch.) Stay safe.

I clean guns with soap and water on occasion including plastic fantastics.
It is certainly not necessary every time you return home from the range. After a number of thousands of rounds I do a complete tear-down to inspect those items not normally visible. Prior to reassembly I wash everything down with Simple Green, rinse with water, thoroughly dry then lightly oil and reassemble.

It is not necessary to do what I do but I do it anyway.

Spray or soak with plastic safe solvents are the easiest and don't require tear-down. Kerosene is a good solvent to use if the spray is difficult to locate in your area.

No offense taken, I do tend to be a bit obsessive about such things, whether it be the maintenance on my truck, Harley, boat, house, etc..I just tend to go overboard, but that's just me. Thanks for all the input.