Hello. Welcome to hcm.
Snuff is a tobacco taken by nose. It is just a alternative of smoking
. Though effects to lung are not present,the tar wil be absorbed in the body causing varied effects.
There is little research on effects of snuff on systems of our body,it cannot be positively ruled out that it causes decreased response to antibiotics.
If liver transplant
was done,then your might have normal life span and he needs to be motivated to make his life more meaningful.
I advice you to make him stop this habit as precaution is better than finding a cure. You can try again for de addiction centres as many addicts once shying away from these centres, wil like it when they feel they are accepted by its members.
All the best