Well, armed with pocket-crippling gel and a pair of transparent myteeth lookylikey gum shields, I've just tried the first treatment. Actually, it didn't look too bad - you could only see around the gum line I had these shields on, but when I spoke, I did sound as if my tongue had grown twice the size. I always sounds pretty drunk, so no change there.
And it works! Just been inspecting the result - first time, remember - and I'm sure I can see a difference. Knocked the postman off his bike when I flashed him, anyway ....
He liked the teeth, too.