Try ordinary nail polish – you’d be surprised what an effect this can have on a male – it means he doesn’t chew unconsciously, because he “sees” the color coming towards his mouth.

Only 3 replies! As a nail biter myself, mostly stress induced, I would have loved a few more solutions

Maybe brightly colored nail polish? It would catch his eye every time he absently starts to bite, and might help him break the habit.

yeah hopefully you can get him to stop. he needs to find other ways to relieve his stress.

Remind your hubby of all the germs that are under his nails (even with frequent hand washing) that he is putting into his mouth!
When he is out pottering in the garden – remind him.
When he comes out of the toilet – remind him.
When he scratches his head – remind him.
When he is changing the oil in the car – remind him.
When he is painting something – remind him.
Any activity he does remind him, that’s getting under your fingernails then into your mouth!
Eventually he will be so disgusted , or sick of hearing it , that he will stop.
You may even find some videos on YouTube to show him.
Otherwise a chat with your doctor could do the trick.
I stopped after my parents constantly reminded me about all the germs I was putting into my mouth. I am now over 20 years nail biting free!
Good luck.