lol I had to post a reply caues you've totally made me giggle. Firstly I think kids will pick their nose regardless and secondly it would be great for you to use a tissue or hanki all the time that way your DS will see that often and hopefully you wont have a challenge getting him to use one when he has a cold or boogers up there KWIM, it's actually a good thing that you will have an opportunity to teach him cause it'll be much nicer than him picking his nose and eating it or wiping it on his sleave!