You can certainly use a sprinkle skirt instead; exactly how you mimic the look of a cupcake in clothing or costume is really up to you. As long as people "get it" when you explain that you are dressed as a cupcake, anything goes.
It won't kill them, but it can serve as a repellent. Lime-scented washing detergent would work as well. Also, another repellent is peppermint oil, peppermints, or anything peppermint-scented. Any citrus...
Mulberry leaf tea is a green tea, and a very healthy one to boot. The only catch is that the leaves must be washed very thoroughly before using them. Mulberry...