Where do you live? Simple Green goes by different names in different places.
Personally, I use 90% acetone for paint stripping. totally fine for metals, and fine for the BF Resin (for, say, less than a day)
You don't even need to soak! You can literally dunk them for 5 seconds, then gently scrub with a brush, re-dunking if the primer is stubborn.
DO NOT use on any plastic bits (some of the new figs are plastic, and say, Shurtzen, some old tracks etc)
Yeah, I've used 'em a bit here and there, not a fan in general, had the same issues with them I did with the tamiya pots (Oddly, Tamiya and Testors are my favorite primer brands)
I also really like Tamiya for thinning down into Airbrush paints.
I just mail-order the vallejos, which I prefer for actually painting with a brush
