As I am no longer a young man, I frequently find that my finger joints are swollen for a few days after judo practice. This is more a chronic overuse issue that has developed over years than an acute issue. I generally try to grip loosely and hold with the pinky, ring, and middle fingers, but increasing find my pinky and ring finger joints suffering. I understand this is a common injury in gi-grappling sports, but are there ways you adapt or things you do to lessen the severity? I am considering trying to switch more to holding the person rather than the gi, but I am looking for any wisdom.
My first tip for you is about how you can protect your joints. Well, first try to relax your arm. If you have relaxed arms this will make it much harder for your opponent to break your grip. The grip is much more than the strength of your fingers and to break the grip your opponent must stretch your arm to the end. This technique will avoid it because you can let your arm go without loosing the grip on your hand and fingers.
Another tip is to tape together your fingers to make them stronger. By tapping your fingers together you have better joints. Just remember you are the only one who knows how much your joints hurt. Be smart and release your grip before your opponent breaks it.
I have been training BJJ for more than 10 year. My hands not luck nicer. Sometimes I still feel my joints. When this happens I try to tape my fingers together and I release my grip easily just so it doesn't hurt any more.
I recommend: Joint Supplements + Hand exercises.
Chronic overuse is chronic overuse. You cannot just solve it magically in days, these things usually take time and effort.
You could try lessening your usage of your individual fingers by kind of pressing your fingers in towards each other so that each finger supports the fingers adjacent to it (e.g. pinky supports ring finger, ring supports middle, index supports mid, etc.). Pretend all of your fingers and your hand are just one piece, like you are wearing a mitten. This will mitigate more of the side-to-side forces that your joints will not handle as well (and become inflamed).
You can try chinese meditation balls. When you use them, allow yourself to notice that the more you relax the more it comes with ease to facilitate them not touching. That is, the proper technique is to move then around in a circle without touching. Going one way, then the other. You can also try pushups on your fingers or any other exercise that a mountain climber might use.