I also used the squirt bottle, for my puppy (Lily, R.I.P., my baby!!) that would not stop barking whenever she wanted something or was unattended..
I would squirt her until she was soaked, then I'd have to blow dry and brush her out! Well, this was happening 3-5 times per day, and needless to say, this was more punishment to me than her; she just kep right on barking!
I also used the cans. My baby, Daisy, would yap when I left her outside in her potty pen. She would yap, bark, and if it was raining, she would howl! I was told to get change and put it in the can and shake the can eveytime she barked. The problem was she only does it when I go inside, not when I am standing there- so they said
throw the cans at her pen to "startle her" and get her to stop...that didn't work, either! She would stop barking about 2 seconds, while the can was in the air, then when it would land, she'd run over to where it was and put her feet thru the pen and roll the can and keep barking, almost to say "I want to be outside of this pen like the can is!!". Quite Annoying! A few times, the can landed in her pen and then she'd roll it around, while barking, and annoy me!!! The only good that came out of this was that I improved my throwing hand!!!
Needless to say, I just don't leave her outside to go potty! Now, she knows she has 1-2 minutes to do hewr business, or she'll have to hold it, and we have 0 problems!!
If the can works for you, use it!
If the bottle works, use it!
Just don't ever hit them or they will learn to hate what hurts them!
Love your Yorkie babies like they're your kids!!