hey 22 boomer that mag block looks similar to my mag block thta I got earlier this year from rmw xtreme.
I just spray the heck out of my upper with carb cleaner or brake cleaner and then spray in a little oil and clean thoroughly maybe once a month.....6000+ rounds of milsurp and no corrosion on mine...and my barrel is chrom moly......and I shoot it two or three times aweek at the shop......usually go burn a mag at lunch as stress relief......
and I never thought of windex....I'll have to give that a shot as well...LOL
If you live in the desert areas of the US then you don't really have to worry about corrosion, but in places like LA and Florida where you have to worry about rust even on clean oiled guns then corrosive ammo gets scary, causing surface rust in hours.
I shot some corrosive commie surplus in an AK and accidentally left it sitting uncleaned for a week or so during the winter here and there was rust in the barrel, but no pitting, just very light surface rust.
you can simply purchase cleaners you would use for black powder,works for me.