It has been my experience that all Loc Line arms creak when moving them around but since I do not capture the audio to the NLE, it doesn't really bother me. Don't know if spraying them with something like WD 40 would accomplish much, I doubt it. Never the less, I prefer loc line arms to ultra lights as I can move them to different positions much quicker. Nocturnal Lights also have similar arms with each piece having already drilled draining holes.
All my locline arms have creaked.
I would not suggest WD40 as the arms might not hold their position so well.
I like Locline for their flexibility, quick movement and variable positioning. Also good for out of the water as you can just roll them in a circle with the light head tucked out of the way alongside the housing to protect them.
The creaking is not a problem as you rarely want to use the footage during the couple of seconds that you are repositioning the lights. The camera will be moving and the light direction changing, not something you want in the final cut.
The creaking sound sometimes can be a plus in editing. Say you shot some "quick grab" footage of some interesting marine life and then, once the quick grab is in the can, you repositioned the lights to get an even better lit shot. Then, during editing, you want to find the better section, you can see the creak as a big bunch of seismic activity in the audio track...