挖鼻屎 can be good or bad..good is you remove the mucus; bad is you can directly introduce bacteria into your nose through your finger after touch some contaminated objects. To eat鼻屎 is very nonsence idea... it is same as your shit and urine... why we human have to excrete shit and urine all this?? because is useless substance and even toxic to our body.. since is useless and toxic why we still want to eat them leh????