I do! I do!
When I was teenager I became quadriplegic and after years of physical therapy when all has been said and done, my left hand is little to no help in hair styling (though generally I'm fine otherwise).
So, expert advice!!!
1) I do almost everything with my head flipped upside down. Creates easier access for the functioning hand/arm.
2) Headbands! so easy to use.
3) Long scarves: It takes practice but if after your hair drys, you flip your head over, hang the scarf/rope/shoe lace/whateva over the back of your neck, use the one hand to loop the ends as if you were starting to tie your shoes, put one end in your mouth, pull the other end so that eventually the scarf contracts around the crown of your head creating a pony tail, use a spider clip to secure at the top or bottom.
4) When i broke my good arm I could still take full on showers and keep the cast dry by tying a plastic bag over it. If your splint isn't too big, maybe you can put a plastic glove over it... Like the ones people use to wash dishes.
5) Also I used to run a comb through my hair while shampoo or conditioner was in just to make sure everything got cleaned.
Hope that will give you some ideas on how to do it one handed. Good luck