I’ve had the same Perlick 525SS faucets on my kegerator for years and have done absolutely nothing to them except for the occasional soak ‘n scrub. Over the last few kegs though I’ve noticed that the handles moved with some stiffness, and they had to be pushed closed a bit. In fact I lost a few gallons of porter on the floor one night because the faucet didn’t completely seal.
Before tapping my newest beer I took a harder look at the faucet hoping to be able to figure out how to fix it. It’s a very simple device with only one moving part so I was able to sense that the ball & socket joint made by the valve and body was sticky. On my faucets the valve does not come out of the body so I could just barely see the o-ring that makes that seal. Using a toothpick I shoved some keg lube down in to that joint, and after working it around the valve had that brand-new feeling. It slaps closed now with far fewer drips than before.
For reference here is a link to Perlick’s parts diagram. I lubricated between the o-ring and the upper ball in the valve. The lower ball makes up the actual beer flow valve. Here is an annotated image from that page in case the URL changes.