Hello,
I am very new to this site and this the first time to post on anything! I use litter boxes filled with feline pine pellets, I was having a hard time just training in general even in good weather!! And the breeders I got my babies from didn't use pee pads so they thought they were just great toys to rip up and run around with they couldn't believe I actually wanted them to use them for a potty!! So I read about litter training dogs and thought it couldn't be any harder than what I was going through!! They also have dog litter - but it is way more expensive and doesn't work any better than the feline pine in fact I think the feline pine works better. I got an ex pen and put a litter box in it and as soon as I sat it down they sniffed, jumped in and peed!!! I was soooo happy, now that intial great moment doesn't mean we have never had an accident but it only took a week or so and they were 1000% better than they had been. The only thing is they are a little funny about it being dirty if you don't get the poop out regularly they might poop beside it. And yes they will still go outside as well.
Well I know that there is not any one way that will work for everyone but I think that Yorkie's know what they like and if you are having problems esp. with potty training if one way is not working it might be worth it to try something different you just may not have found the way they prefer. I know I was knocking my head against a wall I tried everything I could think of until I found this.
My babies are Max, Piper and Emma