What are you worried about? That the electricity will leak out and make a puddle?
OK, so you want to be fussy. Could you show me a primer that's UL Listed? Did you know you're supposed to use listed cement?
As for the instructions ... UL has made clear, on many occasions, that they do NOT consider any statement along the lines of "use only our stuff" to be part of the listing instructions. This point was well developed in the "classified breaker' debacle.
As far as UL is concerned, you may use ANY product listed for it's purpose.
Look to the opening pages of any UL standard,and you will find many other standards referenced. This should tell you that products are tested while keeping in mind industry standards. For example, to ensure everyone uses the same threads on fittings. Or, that "schedule 80" means the same thing to everyone.
