We got a 5 year old husky about a month ago, but also have a Shih Tzu that I have since 8 weeks old. I have only trained one dog, so I don't have too much input, but as far as potty training goes, Shih Ttzus are very hard to train. One thing the vet suggested was to make it a "happy" time for her and she would get excited about it. SO what I did was ask her if she had to potty, but say it real lively and playful. This definitely helped! It just takes alot of patience.
When we got our husky a few weeks ago I felt bad for taking him away from his "buddy" who he had been with since birth. (We got him bc the owner just couldn't handle 2 huskies anymore.) I asked the owner if she or her other husky could sleep with a blanket for a few nights so it would have their scent. We put this in the kennel with him and he was fine and our first couple of nights went well. However, he was already kennel and potty trained, so we only kennel him when we have to leave the house. This probably didn't help much, but I wanted to mention about the scent thing. I noticed that you put your shirt in there with the puppy, but could you get something of the mothers or other puppies to put in there?