Ah sorry to hear that
Yes I have always said no viewings 48hours previous, shoes are left at the front door, (which we anti bac with cat cleaner 99% germ killer before & afterthey place their shoes down) comfy old clothes are worn and we provide anti bac on their hands. I dont know anyone that would let people over as young babies with eyes not open! Thats like a week old?!
I dont even let my family come over (and they have no pets) incase they bring something in when they are babies!!
I also find that the kittens are more able to go up to new owners and bond with them as kittens, then it takes a few mins when they are older, I always say that its like they get to a certain age and realise that Im not actually a cat!!