Hello, thanks for your question today! I am Dr. Drew, and I am a licensed veterinarian. I'll be happy to help you in any way I can.
While Xanax is commonly prescribed for anxiety and phobias in dogs, and is relatively safe,
it is not a sedative,
and will probably not help you to accomplish what you are describing.
there are no over-the-counter sedatives available for this purpose, but some dogs may get a bit drowsy with Benadryl, 1mg per pound of body weight.
Xanax, when dosed to dogs, would be dosed at roughly 0.5 to 1mg for a large dog.