Don't do it....
Not sure if I can mention or link to it, but there is another website where they Talk about Glocks (should be enough for you to find it), and they have a thread EXACTLY about the use of Simple Green for cleaning as described by Dunlap in the AGI video you are referring to...
Do a search on their site for "windex" (OP had asked a question about that which lead to the AGI video)...and you will find it..
Seems the Simple Green has failed some military testing because it causes embrittlement of metal....(hope I'm OK here cutting and pasting the military report" - IF NOT - please delete, mod)
"5. FOR EXAMPLE, THE MOST COMMONLY USED NONAPPROVED CLEANER
(SIMPLE-GREEN) WAS TESTED AND FAILED SEVERAL SIGNIFICANT REQUIREMENTS CONTAINED IN MILITARY SPECIFICATION MIL-C-87937. THE MATERIAL FAILED THE HYDROGEN EMBRITTLEMENT, LOW EMBRITTLING CADMIUM PLATE, EFFECT ON PAINTED SURFACES, AND SANDWICH CORROSION TESTS. THE FAILURE OF THE HYDROGEN EMBRITTLEMENT TEST WAS ESPECIALLY DISTURBING BECAUSE EXPOSURE TO THE CLEANER CAUSED A TENSILE BAR SUBJECTED TO A LOAD TO FRACTURE AFTER ONLY 2.5 HOURS OF EXPOSURE. TEST CRITERIA REQUIRES THE EXPOSED BAR TO WITHSTAND A MINIMUM OF 150 HOURS OF EXPOSURE WITHOUT A FRACTURE. THE TENDENCY OF THIS CLEANER TO CAUSE HYDROGEN EMBRITTLEMENT IN HIGH-STRENGTH STEELS COULD HAVE CATASTROPHIC CONSEQUENCES WHEN IT CONTACTS HIGH-STRENGTH STEEL FASTENERS OR CRITICAL LANDING GEAR AND FLIGHT CONTROL COMPONENTS. FOR EXAMPLE, THERE IS STRONG EVIDENCE THAT THE FRACTURE OF A CRITICAL ATTACH FITTING FROM CORROSION AND EMBRITTLEMENT WAS CAUSED BY "SIMPLE-GREEN"
BECOMING ENTRAPPED IN THE AREA FOLLOWING WASH OPERATIONS. THE
CLEANER'S INABILITY TO PASS THE SANDWICH CORROSION TESTS ALSO
DEMONSTRATES THE POTENTIAL FOR NONAPPROVED CLEANERS TO ACTUALLY CAUSE CORROSION INSTEAD OF PREVENTING IT. OBVIOUSLY, THIS DEFEATS THE PRIMARY OBJECTIVE OF THE ENTIRE AIRCRAFT WASH PROGRAM."
Anyway - seems Dunlap and AGI blew it big time with this cleaning method which can have serious and lasting consequences on the gun.
Again - DON'T DO IT...
