Welcome to YT
All dogs bark but some a little less and the yorkie isn't one of them.

I think Ellie Mae is right that your pup is way too young for a water bottle. My girl only barked to alert me and if some one was at the door. She saved my life once alerting me to smoke in our apartment building. I kept saying shhhh that's ok Crystal and she would not stop and sure enough the fire men were in the hall and told us not to open the door and to put something under the door to keep the smoke from coming in that night. She seemed so proud of herself. There job in life it seems is checking the door and protecting us.
Good Luck with your little one, I'm sure Baxter will be fine. Do post pictures when you have a chance.