I love using Advantage on my ferals because it not only takes care of the fleas, but also ear mites and some worms. But....I have never tried putting it on the one feral who won't come near me. I have several ferals who will let me pet them (on their terms), but won't let me pick them up, so for them I start petting them, and when they are really into it I keep petting with one hand (using that hand to open up a spot in their fur) and then using the other hand I very quickly squirt on the Advantage. It is a bit of a juggling act, but it works. I found that Frontline had a strong enough smell that they knew when I had the open container in my hand and would stay away, but the Advantage must not be so obvious because they don't shrink away when I have a open vial of it in my hand.
If the cat is in her bathroom already, she might try a full body press. Put on a pair of sunglasses or protective goggles just in case he gets wild....you don't want your eyes scratched...and then sit on the floor on knees with ankles crossed in back, quickly grab cat and tuck between legs and under body, using body to hold him down (this is how I pill ferals). With one hand holding head down use other to separate fur and apply Advantage. When finished run like a bat out of hell!