If you fish from a kayak, then your gear is going to get wet. It's just the way it is.
The mere fact that we are just inches above the water makes it near impossible for our gear not to get wet. Whether it's simply the drip from your paddle, to your hands, on to your reel, or from the splash and/or handling of a fish, to even dunking your reel by accident.... it is inevitable. And if you fish the salt, like I do, it is of the utmost importance that you rinse your gear promptly after you get off the water. Through the years I have ruined more equipment than I care to admit by failing to do just that. It could have been just laziness or simply just fatigue from paddling/fishing all day, regardless it was getting expensive. As I accumulated nicer equipment, I realized that no matter how awesome the rods and reels were, if I didn't maintain them, they would turn to crap just like my old stuff.
Upon accepting this simple nature of the game I kept about a dozen used water bottles in my car filled with tap water so I can pour it on my gear while packing up the car at the end of a trip. I didn't want to wait until I got home because sometimes it would take quite a while before I got back or I might not be headed straight home. After using the bottles for most of last year, I got tired of empty ones rattling around in my car, not to mention having to refill them all constantly. So when the light bulb came on I was like "Duh, why didn't I think of this sooner?"
I've been using a garden sprayer for several months now and it's getting the job done well. I found a small one gallon sprayer at the hardware store for around $10. I don't have to fill it up as often since I'm able to focus the spray on exactly where I want instead of dumping water all over. Also, it doesn't take up too much room in my little hatchback. I don't even take it out unless I have to fill it up. It stays bungie tied inside and all I have to do is pump a few times for pressurized fresh water. The adjustable nozzle is great for my rods, reels, radio, various tools... anything sensitive to rust or corrosion. It even comes in handy to wash off sand on your shoes, feet, hands, sunglasses, whatever. I will still take apart, clean, oil and lube my reels once or twice a year, but in the mean time my garden sprayer will help.