Check out this interesting info on a dye made from madder root called purpurin. "The results showed that, at sub-lethal concentration (3 µg/ml), purpurin blocked the yeast-to-hypha transition under hypha-inducing conditions. Purpurin also inhibited C. albicans biofilm formation and reduced the metabolic activity of mature biofilms in a concentration-dependent manner." http://www.ncbi.nlm.nih.gov/pubmed/23226409
How about knitting a "sub-lethal sweater", out of some vivid purpurin/madder dyed skeins of yarn:
Since I don't knit, dipping a shirt, blanket or something I already have sounds better : ) Maybe a double dip.
Purpurin is a red anthroquinone dye used as a biological stain. It also has a very colorful past in ancient woven tapestry, medieval paintings, British red coats, and even found in king Tut's tomb: http://iranpazirik.com/htmls/madder.htm