Thousands run the womans only 5k each year for the breast cancer charity, but in many ways the people tending to run those races are, on the whole, not the same as you get on a regular running forum such as Runnersworld. As much as I love Viccy Park, I don't think I could persuade many people to sponsor me to run 3 miles, a distance I do as a recovery day. Whilst I applaud your efforts and wish you well, think perhaps you should be looking at a different group of people for which 5K would be a challenge.
Any chemist Scott? and what do I ask for - I usually just go in and ask for imodium to be honest - is taking that cheating or is it allowing me to compete equally with runners not needing a P** every couple of miles!
Seriously though, does anyone remember the adverts for Maxim from the early 90s - they ran an advert along the lines that it would help knock 10 minutes off a 10 mile time. I never did get down to 47 minutes but there you go. It just shows though that people are prepared to try anything that may give them an advantage.