Well, I like the product idea, but not sure about people bringing their dogs with them.
I picture a room full of dogs who are all in an unfamiliar environment, don't know each other - could be risky since you never know what a dog is going to do to another dog (or person, for that matter). Yes, dog parks are all about different dogs among each other, but it's different than being inside a house and maybe feeling trapped and "confrontational".

Good idea with treats and accessories, though!
Very unique ~ I've never heard of a home party with that type of product, so I bet there isn't much competition in that area.

Good luck!