You can really use it anywhere, it's just geared more toward use for back & chest because it's easy to spray & you don't need to rub it in like a cream or gel.
yes i have. it helped me alot with the actual pimples (sorry if that grosses anyone out) on my chest/back, but everyone is different. also, it will dry out your hair if you spray some on it by accident or something, but it's nothing too major. all in all, it's a pretty good product.