Blue lock tite

Duct Tape.. Just kidding. I don't know what the fixtures look like. But, could you add just a small dab of something like clear silicone to the head of the screw rather then the threads ????? All you have to do is to keep the head of the screw from vibrating downwards. With the goo of your choice on the outside of the screw head you would be able to slice it off with a knife should you ever need to remove the screw.

IBM had some stuff that was similar to clear nail polish, except with bits of nylon in it. This is what they used on their laptop screws before that division went to Lenovo. Downside is that you could not reuse screws, as they were coated from the factory, but they would hold in place and not come loose.

It works well on machine threads (nuts and bolts), but I've never tried it on screws where it means dissimilar materials. The chemistry of Blue is about adhesion to smooth metal surfaces.

Ductape wrote:
Green penetrating Loctite is a more appropriate strength for small screws. Silicone is a lot easier to find.

Agreed, and the 290 will wick so can apply after installation.

Thread locking products have historically been cyanoacrylate based, and cure in an anaerobic environment.

I would try either a Geocel or silicone type caulk.

Agree, wrong app for loctite unless you don’t want to loosen them again. Those pot metal fixtures and cheap screws will likely leave their threads attached to the wrong piece after loctite.
Use a less aggressive adhesive or vibration dampening stuff like silicone or elect tape.

Shoe Goo

I'd use a more conventional sealant like silicone or a urethane. The bulb may go out in the fixture at some time and Loctite is known for it's strength. Putting a small bead at the connecting nubs is maybe all you need to eliminate vibration and offer peace of mind.

Small rubberband at base of threads tighten the nut up to it

Green penetrating Loctite is a more appropriate strength for small screws. Silicone is a lot easier to find.