PU is NOT about HITTING ON girls. This is a common misconception among people. It is instead about creating an emotional state/framework. This emotional state/framework (which girls work within) help you to lead her in the direction to want to go.
Think about it. If you walk into a room where everybody is happy, having a good time - you suddenly find yourself becoming excited and having a good time also. These people have created a state/framework of happiness/joy. Now, all you have to do is to work on a smaller scale - one girl.

If you want to get her to:

Get Horny
Become attracted to you
Become intrigued with you
Become Interested in you

You need to break her state and bring her into yours. You can accomplish this by:

Telling stories
Using quotes
Building Rapport
Mirroring
Weasel phrases
Time distortion all RJ

By using these above methods (this is not a complete list, just examples) you bring her to 'that state'. For example : if you are trying to get her horny, you might say 'I don't suppose you could feel incredibly horny and feel all the desire building up in you. And the more it builds, the more it feels good. It does feel good, doesn't it? As the fire begins to spread throughout your body to certain...places'

NOTE : Never have you 'hit on' her. You are talking, implying, but never actually hitting on the girl.