Thanks to Fake Nails.
Among other things, I'm also a compulsive nail biter. And I really hate it.
For me, those horrible nail polishes have never worked. They don't stop me from biting my nails. And if I really want to bite my nails, which I usually do, then a bit of a bad taste in my mouth afterwards isn't gonna stop me!
I've found that the only way I can prevent myself from biting my nails off almost completely, is to apply fake nails. This way I physically can't get to my nails to bite them. It helps. And at the same time, I can make my nails look nice. And that makes me feel better, too. I do have to reapply them quite frequently sometimes, but it doesn't bother me, because I know it's the only thing that will keep me from chewing at my nails constantly.
Eventually the nails fall off and you notice how long your nails have grown! It's great. They look a bit gross because they've been stuck under the fake nail with glue all over them. But once you clean them up, you'll be happy! They can be quite frail too, so be careful. But everyone has different nails.
I also find that after I've taken the fake nails off and my real nails are significantly longer, or long enough for me to be happy with them, the want to bite them literally disappears. Because they look nice, I find it so much easier to stop myself from biting them off. Which is really cool.
There have been times though when I have completely ruined my good run on a drunken night out when I've started frantically biting. But if you have some self control that helps too!