Yeah, WD-40 isn't really a lube, it's a cleaner or an un-sticker. If you need to get grit and gunk out of your pivot, WD-40 is OK to use, but blast it out again with canned air and then lube it with proper lube. I use Tuf-Glide on my plastic handled Sydercos with great results. If you have a higher-end knife, or one with metal handles, Militec-1 would be my reccomendation, but really, almost any true metal lube works fine. Before I used Militech and Tuf-Glide, I was using a teflon based grease that was actually intended for food service equipment (a bit thick, but smoooooth) and a bike chain lube called Tri Flow (also teflon based I think, or maybe silicon).