Things people said to me at the doors had more affect on me than anything I ever heard at a meeting.
I remember once, as a young pioneer, another sister and I went on a return visit of hers. This lady knew her bible, and asked so many questions that we couldn't answer logically.... I can't remember the specifics, but it made a huge impression on me.
When I was struggling with serious doubts, someone made a very pointed comment to me at the door. I didn't realize it at the time, but I was struggling to stay 'mentally' in.... and that comment hit home with me so hard that it slammed the door of the WTS shut for me forever. I wish I could find that lady and thank her personally.
A well chosen comment or question might save a doubting JW. But be careful, ITIS.... even if the specific JW at your door doesn't know who you are at the time, if the elders ever do decide to look you up, what you have said previously might very well be related to the elders then. Don't ask anything that might incriminate you.
GGG