This is not
exactly what you are looking for, but this is something I have done a few times and I haven't had any problems with it. Again, I am not a fan of routines or canned material, but this is decent.
the-vegas-pull-club-dancefloor-idea-vt5 ... highlight=
I understand you are looking for things to say during/after grinding, but I think when it comes to dancing, it's less about words and more about action / body language a.k.a how you dance. Obviously I don't know the clubs you go to, but at the clubs on my campus, I usually pick-up girls near the bar and not the actual dancefloor... most of the time, we'll make our way to the floor later in the night, but by then I already have them.
Approaching on the dancefloor, though most people here will not recommend it, is not too difficult. Just go on the floor and have a good time... I'm not a bad dancer so I'll usually club it up and just stick myself next to a girl I think is cute. I'll eventually face her and make eye contact, and while I'm dancing, I'll give her the "come here" motion with my hand/fingers. A majority of the time, they comply. If not, who cares and keep having fun.