Hmm interesting, might be worth a try, but do you have your own tanning bed? Will someone let you use one for this purpose?
Here's a good article about different treatments for yeast in cloth diapers, it is also where I got the link to the website about GSE treatment that I put in your other post: http://www.pinstripesandpolkadots.com/YeastvsCloth.htm
Also are you sure you are dealing with a yeast rash? If it popped up overnight it may not be yeast....with the problems you are having with repelling I am wondering if it was a build- up of detergent residue...