i also coat their noses w/ a lubricating barrier each night and every morning. more often if they are getting a runny nose. my 3rd son - jonah- used to get horrible bloody noses. if he got one in his sleep, it looked like he'd been murdered in his bed. he's also the one that got such severe sinus infections, he's scarred his sinus cavities. he used to be 'that kid' that walked around w/ snot like applesauce hanging out of his nose all winter.
i started spraying out his nose w/ a pure saline spray (my kids hate the neti pot) 3 x's daily and then coating it inside both nostrils w/ aquaphor on a q-tip after every saline rinse. the bloody noses stopped and the runny noses barely last 2 days now, whereas they used to never end. i read that this can also provide a barrier to prevent airborne allergens (or ones on probing fingers!) from lining and entering the mucous membrane, so i began doing it for all my kids. it also helps keep their noses from drying out in our harsh dry winters. if you like to avoid any traces of petroleum in your products, raw organic shea butter works almost as well, tho it gets a bit more of an oily texture as it warms up and doesn't 'stick' quite as well!
and the last best reason for doing this is they don't make boogers anymore! i haven't seen a booger in almost 2 years since i started doing this ! can you imagine having 5 kids and never seeing one rooting around in their nose anymore?! i never woulda thought it possible!