Did you know that right before you get to where the last trick was, you should be on a catwalk and next to a room filled with WORKING turrets.

"... Well that's no matter, because I'm still holding all the cards. And guess what? They're all full houses."

Once you hear that quote, you'll know that you're good. So what you have to do for these quotes is first, kill all of the turrets with the excursion funnel. After you've done that try and align the funnel so that it's halfway going the way you're supposed to go and half touching the wall. You'll know you've got it right if, once inside the funnel, Wheatley begins is quote. If you don't stop yourself on the wall, his quote will get cut off.

So you have to move to your right to make the wall stop you and Wheatley will have time to finish his quote. Then, get out of the excursion funnel, go back up the stairs, and he'll have a new quote! I believe this works a few times before he says that he's not saying another word until you do it right.