Trying to figure out how to achieve leak-free union joints. I'm installing them on both side of the pump so that it can be easily removed if necessary. I've seen one You Tube video where the guy put Plasto Joint Stik on the threads going into the pump body (seems reasonable since this is basically permanent). But for the union fitting is it best to use Silicon lube (so it could be eventually undone)? And lube up the o-rings, too?