I use Park bike grease. It works. Sure it cost more than generic marine grease, but even still I got a 1lb tub for $11 or something, I was already ordering other stuff so it didn't cost more in shipping. That $11 is going to cover me for many MANY years down the road. Worth it, IMO.

I use it for anything around the house I need grease for, too. Which isn't much, but once in a while if I need to use it, its there!