It really should go without saying, but please only do this with an unused tampon.

I remember being in like 4th grade and the teacher showing us a video about the tricks they use in advertising, how they carefully craft cheeseburgers, use spray deodorant on beverage glasses to make them look frosty. The thing that stuck in my mind was fake ice cream. Because ice cream would melt under the lights they actually use a substance similar to cookie dough, like shortening, flour, sugar etc. which is completely edible so you can film actors eating it, and I remember thinking "that doesn't sound half bad, actually."