maybe they should try a humidifier instead... most people are living in very dry air and clueless that humans need between 40-50% air humidity... the sinuses are designed to remove humidity from the air to hydrate head/brain... a dehydrated brain/blood system creates all sorts of psychological conditions!... if you dont own a $5 digital hygrometer to give you exact air humidity readings then you need to get smart!... air humidity swings rapidly and you must have humidity at a minimum of 40% otherwise you are killing yourself!... the weather humidity "reports" is absolute bogus, frequently off by 100%, maybe its glowmonkey meddling?!.. when you breath air less than 40%, every breath dehydrates rapidly, forcing the body to create mucous to send up to sinus to rehydrate sinus, brain, head... yes this is why the "common cold" is patently false and a trillion dollar scam!! p.s. if for some reason you cant humidify the air, like in public space, wear a hospital mask as that keeps you from expelling your hydration, as the mask catches it and allows you to breath it back in!! just a heads ups! pss drinking water does nor directly help dry air dehydration, as the body then needs to create mucous from the water to send up to sinuses to rehydrate brain!