In the supermarket it works without ass grabbing. Just ask the chick anything about certain products and cooking, and you've got a good chance of driving her home, or arrange for a coffee meeting later.
The ass grabbing stuff works mainly in dark clubs and stuff, but it works pretty good. of COURSE you've got to talk to her before, invite her to some cocktail or whatever. But AFTER a while you just got to lay on hands, or she gets bored. Don't know where you guys hang out on Friday night, but my choice is usually dimly lit clubs with nice lounge music and a little dancefloor, were people even dance at the bar when they like the music, even on top of the bar.
Of course I dont grab a chick when the spotlights are on her and it's embarrassing to her when anyone could see it. geez.