The other day I noticed the brakes on my touring bike were stuck as I was pulling another bike out. So I decided to give the bike a check since I might use it tomorrow. All 4 v-brake arms, front derailleur and chain were seized from the salt water (the fenders, they do nothing!). The rear brakes weren't too bad, but the front were right fucked.
I pulled all the brake arms off to clean / lube. The rear ones were quick, but the front required a lot of work. I soaked them in solvent for a while. Once I got them starting to move I dipped them in a cup of iso alcohol which really flushed out the gunk getting them back to moving smooth. Then I dripped in some Triflow.
The brakes are Avid SD5, which are a pretty shitty design. They pivot on an internal bushing. There is a minuscule gap about the thickness of 2 sheets of paper through which water can get in and fuck them up. I've had to clean them several times over the years.
The chain needed a lot of work to get working smoothly.