Yes, I had a similar problem many years ago and couldn't find anyone nearby with a suitable Loctite product. I did buy a reasonable amount of a Rocol product and still have about 80% left.
I started out thinking that locknuts were the way to go in order to align the valves but discovered that a mix of elbows and restricted access made it easier to use Rocol (or similar). I had not used Rocol before and therefore applied some Sikaflex externally around each joint after the Rocol had set.
It worked well and all the valves remained correctly aligned without any leaks. I had to undo one recently and simply ran a blade through the Sikaflex before unscrewing the fitting. Probably overkill with the external Sikaflex but it was really easy to dismantle and gripped both parts in use