Advice on cleaning my pugs sanitary area

I have a pug that is very sensitive about her sanitary area, including letting me wash it. She used to be fine with it until a male pug tried to mount her and it scared her. Now when I try to wash this area she sucks it in as tight as possible and drops her rear. Her rear end is a bit easier to get than her underside. Urine sticks a bit to the skin and her short hairs, so I am concerned about cleanliness and odor.
Does anyone have any recommendations on how to successfully clean this area without totally traumatizing her?
Thanks in advance!

 

Smear some peanut butter or Cheese Whiz on her tongue, then wipe her quickly with a baby wipe or doggy wipe. She'll be so focused on what's in her mouth she probably won't even notice what's happening on the other end.