Sailkote and McLube are the same product. It's not a silicone lubricant it's what's called a "dry" lubricant. You don't want to use a silicone based lubricant on most things on sailboats because they are exposed to the elements and can collect grit. The silicone makes a "sticky" surface that dust, sand, debris, etc. can adhere to. Dry lubricants will typically use some kind of hydrophobic coating that will dry and not create a surface that things can adhere to.
For dry suit zippers, and other zippers on your boat, get some zipper wax from dive shops. Works great and doesn't wash away in the water. I also used to use it on my Jeep before we sold it to live on a boat.
Good luck,
Jesse
