I found a great tool to clean behind and around the splint - a sulcabrush. It has 2 small tips that are placed at different angles, making it perfect to reach difficult places. The only drawback is that the bristles are very stiff and you need to be careful around your gums, especially ones that are numb.
I ordered mine from dentakit.com but they also sell them on amazon.com. No stores near me carry them, unfortunately.
http://jawsurgerysaga.blogspot.com/
