It really depends on how fast I need the integration to happen, if I have time to take it slow no, mostly because all the civies are so use to having cats come and go here after years of rescue and fostering they don't even give the new kid a second look. Now if I have someone already in my foster/new adoptive space that needs to be socialized into the group immediately if not sooner than I will use feliway and calming collars to reduce the stress.
Otherwise I just use short visit through the a partly cracked door, then brief trips out in the carrier to meet and greet etc. Today I was more concerned with stressing Musette out with the changes to her room that she shares with Maxwell and Lady Jane. But it had to be done to make room for a new kitty that will be coming here for awhile until she has her babies and can wean the little ones. I needed to make room to move some of the stuff that is normally in the basement so there is room down there to set up a kennel for the new so to be momma. We are taking her in for a friend of ours that has a dog that is fine with cats but has killed two litters so far to make sure this one survives until the kittens can go to their new homes (its a purebred female with a planned breeding and the kittens have already been placed). Then I will be taking Momma to be spayed and seeing the little ones off to start their lives with their new beans. The only way I would even agree to do this was because I was being allowed to spay the mother and hand off the kittens. I was able to talk to our friend that if he couldn't keep the dog from harming the kittens then he had two real choices either spay and keep the mom or sell her as a breeder to someone that could breed and raise the kittens safely. He decided that he loved Hazy (the mother) enough that he wanted her as strictly a pet purebred or not.Just so you know this isn't someone that let his cat get pregnant just to be able to see a cat have kittens, these kittens were spoken for way before the first litter was killed, he hadn't even intended on her being bred this last time, but she was being pet sat at the home of the stud cat while he was out of town and no one realized she was in heat until it was too late.
Mel, Maxwell, Musette & The Fur Gang