(Diatomacious earth) is great for deworming, just make sure you get the food grade kind. It is also great for mites. I give it to all my farm animals it is really good for them google it for more info.
My chickens love Meow Mix, that is what I feed my cat and they usually scare her off. I guess they have strength in numbers. lol I don't give them much though. For extra protein I usually give them a hard boiled egg. They love that too.
I've done both mixed with the food as well as set it apart. Both worked for my flock. If you're tight on space I would just mix it with their food. I have two Austrolop hens I have isolated due to bad feather loss that is what I'm doing and they are managing great.