Training blind and deaf puppy not to mouth

[Otterotint]

I recently got an eight week old mini Australian sheapherd who is blind and deaf. I have no experience with handicap dogs, so I'm looking for all the advice I can get. The one thing I haven't been able to find any information on is how to train her not to chew on everything. I realize some mouthy behavior is to be expected from these dogs, but right now she is the typical puppy chomping down on everything she comes across. I've been doing the double tap on the nose and walking away and/or redirecting her to a toy but I see no difference in the behavior. Maybe I'm expecting change too soon-it's been awhile since I've owned a puppy? Also, does anyone have opinions on whether it's best to keep these dogs with another dog or not? I've read conflicting things where some view it as mandatory and others don't even really mention it.

[critters]

I've found that my more severe handicappers NEED siblings; for instance, a deaf one can get cues from the rest of the herd when stuff's going on, and one with cerebral palsy (cerebellar hypoplasia) can get help staying clean or can lean on a sib for help standing. Can't help with the mouthiness, though...