FYI I use unflavored baby gas drops in my brewing (or I did when my BK was smaller...) It's cheap, and if babies can eat a few drops, then a few drops in 5 gallons shouldn't be a problem! (So the theory goes, although I have no idea what alcohol might do to the remaining portion of it during fermentation...)
There are other ways of controlling foam, but most are kind of a bother. I recommend looking into a bigger BK when you can manage to. Until then, a fan, some spray, being careful, etc. all make it possible to control boilovers without the chemicals.