The Bear's Den fly shop in southeastern Mass. caters to a lot of salty flyrodders and they sell a lot of this stuff for reel care. I haven't used it myself yet but I'm planning to this season.
Salt-Away Fishing Equipment Spray at BEARSDEN.COM
FWIW, when I was getting my first rod for the salt, I was advised to get an 8 weight. I did, and I found it okay for a lot of inshore situations, but when the wind is up it just doesn't have the oomph to get the line out. Also, if you're lucky enough to tie into a 30 lb striper in the surf or a rip it may not have enough backbone to bring the fish in. (Haven't hooked one that big yet myself, but as the Boy Scouts say, be prepared.) I think a 9 is more versatile than an 8 for your first saltwater rod. A 10 will be too heavy for a lot of fishing situations and will tire your arm and wrist out more quickly.