When it comes to removing old thread locker and other gun, I find pipe cleaners really kind of suck. I've taken to using precision brushes from McMaster-Carr:
...because they are small enough to fit inside the threaded holes on most slides and durable enough to allow you to actually scrub well enough to remove a bunch of crud.
Great tips in the linked thread on Loctite and fasteners, and here on using the brushes for thread cleaning.