Here are the gig grips for snare drumsticks:
giggrips.com/
Simple idea but a good idea in my opinion. Just adapt them to tippers. I think they would be especially helpful for top end technique. Make your own. Perhaps someone will come up with a "tipper gripper"?
I use "O" Rings that can be purchased at any hardware, plumbing supply store. They are used for sinks. The largest "O" Ring made is about 2 inches in diameter. Simply take the "O" Ring, squeeze the middle together (figure "8" shape) and bind it together in the middle with electrical tape. It works the same as Gig Grips but costs about $1 dollar to make. I have several to avoid putting them on and taking them off different tippers.
I would recommend everyone trying them, arthritus or not. The bottom line is bodhran playing is an atypical hand and wrist motion that frequently leads to problems. Many of the professional bodhran players develop hand, wrist and/or elbow problems. When I use these on your index finger, I become unaware of any grip issues. The same is true if I am doing trad McDonagh style playing with the thumb used as an anchor finger.