I like the idea of the hex bolts rather than these locks. I've had the locks on for less than 1 year and three of them have seized solid. Most certainly you need to lube them -- I'd suggest that white lithium spray lube. The rubber covers are not UV stabilized and will rot off in less than a year (mine did). I was able to get 3 of the locks working again with PB Blaster (it's the stuff the muffler shops use to loosen bolts).
One of the stupid things with these locks is the keys. For 2 riggers you get 4 locks and 4 different keys. Problem is, all the keys are different and they are extremely flimsy and while the keys are numbered, the locks aren't. So, when you have a sticky lock and no idea which key works it can be an extremely frustrating exercise trying to get the riggers off. I ended up having to use a saws-all and cut the plastic tabs off the head of the fastener to get the lock with the broken key off.
I now need to fasten my riggers to the boat again -- any idea where to get Stainless hex bolts?