I ran into this problem. I couldn't find the Locktite product anywhere.
Methylene Chloride does it. You can find it at an Auto Paint Store. It's called Aircraft Paint Remover. It bubbles as it works and turns the hard Locktite into a snot like consistency. Paint it on and let sit as per instructions (I think about 10 minutes). Wipe off. Repeat as necessary until clean. Doesn't affect blueing but feel free to test on a tiny area first. You might need to spray out the screw holes with Gun Scrubber using the small straw that the can comes with.