Thanks for the responses. Finally getting back to this after the holidays.
Usually what will happen is I will actually see the phones sending out a broadcast, so I know the they are not turning off wifi. I know when a phone is in the area and I even know its MAC address. From time to time the pineapple will work, but it is not often. I'd say I can grab an unassociated client 20% of the time. When I do get the phone to associate, I can locate the phone quickly, otherwise I have to wait around for another broadcast packet and very slowly close in on it.
One thing to note is that almost every phone I've found has been in an idle state. Most people don't realize they have brought the device in with them. I'm starting to suspect that some devices will send a broadcast packet but will not respond when the device is in an idle state (ie Turned on but not direct use). I do not know if this assumption is true.
However, I'm still curious if there is some way to craft a transmission to these idle devices and forces them to talk back. Even if the response is "Shut up and go away. I'm not talking to you," that would completely change the game for me. I have no desire for the devices to associate in the first place, I just need to get them to be chatty.