ok, so you got him from a rescue shelter and he is going to be wary of you especially if you have only had him a few days.

only use the bottle when he does something you dont want him to do and when he stops, praise him and give him a treat. you can use very small pieces of cheese. he will learn that when the bottle sounds, he stops the unwanted behaviour he will get love and most importantly a treat!

try the other exercise i suggested in your behaviour post, because the soon you get cracking on this he will learn to trust you and the rattle bottle will be more successful.

just keep on trying and be positive about this, because patience is a virtue!