you can blow with two finger
You have to whisper in the library so you won't disturb people who are reading.
you would use it as any other whistle, just blow into it. however, it does not make any noise to us, but dogs can hear it
Throwing a stick for the dog to get it is one easy way to make a dog move. another way is to whistle or shake dog treats in a can.
dog whistle
Yes, only if used along with a proper training program. No one dog will take to the whistle right away a cycle of positive reinforcement along with the whistle needs to occur. The best thing is to try and associate the whistle with something good/bad depending on the type of training you are doing.
dog whistle
dog whistle
There is no best frequency. If you train a dog correctly any frequency the dog can hear will control it. Your voice, whistle, 'silent' whistle. All are acceptable.
Depending on what type of dog whistle, they probably can hear at least some of the sound frequencies. Although I know of no research on this particular subject it is entirely likely that they can.
dog whistle
This'll Make You Whistle was created in 1936.