I apply flea products to my furries regularly(whether they have little vsitors or not).
I used to have a terrible time doing the cats until I decided to cover their head with a towel. This worked brilliantly and I still do it with Tuffty. She'll stand still, growling for all her worth, whilst I happily part her coat and apply the treatment- once the towel is removed she runs off growling but at least I know I shouldn't be bothered with fleas!