*IF* you subscribe to the belief that the Smith and Wesson-made M&P is a least as good as a Glock, you then therefore should be able to believe that this is absolutely fine for cleaning your gun and no problems and in fact a good way for thorough, thorough cleaning.
Glock people have been doing this for YEARS and even dishwasher'ing their Glocks. For years, for minimal problems really.
I myself thought, "Oh my I'd NEVER DO THAT!!" when I was a new Glock owner and shooter, 4 or so years later, my gun was filthy and i was tired, and I thought... hmm... why not... and I nice bucketfull (not really a bucket so much as a container, gallon or two size) of warm water, Simple Green, and a squirt of dish soap liquid... all my Glock parts in there, a nice washing and scrubbing with a toothbrush... then a good warm water rinse, it was totally clean and degreased. Purely. Cleaner any time I owned it since it was box-new. I bought a can or two of canned air to spray it out just for thoroughness, I lubed up properly according to Glock specs, and I was good to go. And someday I'll do it again when it's necessary.
I am a Glock guy first and foremost but love my Shield and carry it more than my Glocks. I believe my Shield could handle this any bit as much as the GLock, and someday when my Shield is older and dirtier, I will do the same thing and surely be satisfied with the results.
I wouldn't use toooo hot water, wouldn't use toooo harsh cleaners, and wouldn't do it often or more than it was really needed, but surely will continue doing it.