This is going to be a strange but useful post. Lately I've been chewing my fingers with stress. I really can't help it and I don't realise that I'm doing it. I decided to go back to the item that helped me when I used to be a biter.
Nail the Habit (which I got in Superdrug for £2.49) would remind you of those nail polish remover pots from Nails Inc and Bourjois; it's a little tub, with a sponge and some really foul tasting liquid.
And it really does work, no sooner has the liquid dried you're screwed! You can't even enjoy a bag of crisps without tasting the nastiness of this stuff, but that's not a bad thing lol.
Using this has really helped me to stop chewing at my fingers again, cuz no sooner do I put my hand to my mouth, I'm turned by the taste that accompanies it.
I'd highly recommend this for anyone trying to stop biting their nails, my poor hands are starting to look a whole lot healthier again.