Very good Sodo... I like the miniaturization mod! So that gold finish is a Zinc plating, eh? Just curious.
Well that fitting looks "gold" because of the lighting. It was a bright silver in real life. BUT there are 3 (or more) colors for zinc plating, Yellow, clear, & black. Yellow is the stuff that looks irridescent gold, like drywall screws. Clear is silver, which will turn gray outdoors, like galvanizing does. I don't know much about black.
Muriatic acid is dilute Hydrochloric acid, its used for etching concrete. A gallon is less than $10. I pour it in a plastic tub, etch/strip the item, and then pour it back into the same jug to use again and again. I store the jug outside so it doesn't corrode stuff in my garage. A fitting like the pic above boils like alka-seltzer intil the zinc is gone, then the steel goes pretty slowly, so dont leave for longer than necessary as you are losing steel. Or etching threads making them rough. In 2 minutes the zinc is gone. Maybe 10 mins light rust is gone. Pits develop in the surface, which holds paint real good. At 30 mins the pits can be significant, screw threads can be ruined.
You wash HCl with water, lots of it. Its strength is in its concentration so dilute dilute dilute. HCl is not a dangerous chemical per se but whatever is dissolved by it may be. Your stomach uses Hydrochloric acid for example. So for small fasteners you could swallow them but that can add a day or so (among other tasks) to your project. Problematic if the wife asks what "waiting for a couple fasteners to turn up" has to do with declining to go out for breakfast.
You can change the focus to your "next welder purchase" with: "I'm becoming interested in the efficiencies of multi-process equipment...."