First of all,
It makes me feel better that I'm not the only one who has dealt with this. I was beginning to worry that something was wrong with me...
Secondly,
The advice i've been given here is excellent. I've already been able to put it to use. It's one of those things where when I am confronted with the situation (as I was today) I just continue with what I am doing very confidently like I have no hesitation and TOTALLY know what I am doing. (Something like "Yeah, these wipes smell so good, are really thick and have never made my son break out at all. Plus they were on sale at Target this week and have this great snap top.") I've noticed that the offending mom usually backs down after that because I make it pretty obvious that I'm not going to trip all over myself asking her for advice. Then I just try to be as polite and loving as possible.
I think I may have been successful in starting to break down this one woman's social barrier. The other woman not so much - I've decided that she is just really mean and not someone that I need to be around. Is that wrong to do? To decide not to be friends with someone? I mean, I certainly would be amicable if I ever saw this person again, but she is not someone I think I need to bring around. When she is around she brings out the worst in other moms, and that is a trap I want to avoid.