I had an assigned window seat.  A woman with an aisle seat in my row (one seat away) arrived and began frantically sterilizing her seat as though she had just completed working out on a piece of equipment at the gym.  She doused the bottom seat, the back, the arm rests, the seat buckles, and even the back of the seat in front of her.  (She was very thorough - the process took 2-3 minutes.)

After fully wiping down the seat, the woman left for a moment to get something out of the luggage she had already put away in the storage area above. While she was doing that, a random woman came and sat down in her newly wiped-down chair, buckling herself in and getting all cozy. The clean-freak woman returned and angrily said, "Excuse me, you're in my seat."  The woman who had recently taken her seat got up without an issue and left.  The clean-freaker stood there and examined the seat as though she was considering wiping it all down again, then just must have figured to impose "the five-second rule" and sat down.

I'm not saying it's a terrible idea to wipe down your airline seat.  I mean, if you do it in a gym, why not in an airline?  But I've just never seen that done before.  Good on her.  I'm sure she's very healthy.