I know nothing about clarinet embouchure (trust me, I'm a sax player and I'm just now trying to learn clarinet). However, I do use a "cushion" on my lower teeth which I fashion from a product called EZO, which is a denture cushion easily found in the dental product section of a drugstore. It requires a little cutting and molding----very easily done and the cushions thus crafted can be used multiple times before you need to replace them.
If you want more detail, contact me off list. Judy
"Already too loud!"
Bruno Walter at his first rehearsal with an American orchestra, on seeing the players reaching for their instruments.