When I was in highschool (around 97) some surge reps came to my school and handed out free bottles. Of course people kept sneeking back and getting more, than the one, they were supposed to. By the end of the day the whole school was bouncing off the walls. And yes, the yellow number 5 teenage rumor was rampant.
There was also some promo near where I was at that time, but I think it was at a supermarket. Maybe buy a 12 pack, get a 12 pack free? Maybe they were giving away 12 packs if you got a coupon from the Sunday paper? I forget.
The school thing sounds like something that would happen at that time. I recall when I stopped in a supermarket near a college campus 2 years ago, near the time when students were arriving for the semester. All sorts of free food stuff. I looked young enough, so I guess that's why it was offered to me. I took a free, full size, bag of Utz brand chips.
Interesting to read the yellow #5 thing was common. I knew of people, even if they were thirsty, would not drink Mountain Dew, Surge, or any cola with Yellow #5 in it. Even if you tried talking sense to the person, saying if it were true then..... blah blah blah, etc. Still, some people were 100% against Yellow # 5 in their cola. They heard, from so-and-so, who heard from so-and-so, who had a brother whose friend became impotent/sterile, whatever due to Mountain Dew and Yellow #5.