Wow thats messed up. I remember doing the "I believe in Bloody Mary" chant with four of my friends when we were about 7. To this day I'm not sure what I saw but whatever it was scared the absolute shit out of me. I recall going round to a friends house for this specific reason in Inverurie in like 1987 or something, we all agreed and went into the bathroom, turned off the light, held hands and did the chant which I think you've got to do around 10 times or something. I was completely unconvinced this would work and naturally the skeptic I took part for the fear of not being in the group. Anyways, we did the chant and after perhaps the 10th time this greeny-white thing actually appeared on the wall for a brief second before we opened the door and let the light in, and ourselves out. Like I say there's no definate explanation of what it actually was but I definately seen this shimmery greeny-white movement on the wall, from that night on I needed a night-light. Not anymore of course