Technically putain means prostitute, but it also serves as a handy exclamation of rage, frustration, disgust, joy, surprise, excitement and more rage. “Putain, ça pue !” is particularly useful to know when around unpleasant odors, which brings us to…
2. Ça schlingue!
To schlinguer is to stink. So, if you want to really emphasize the malodorousness of your surrounding environment (and you probably will at some point), let rip with a “Putaaaaain, ça schlingue !” especially if somebody has already let rip.