Cocaine.hcl isn't GOOD for your nose, but at the kinds of amounts and frequency of use we are talking about, it shouldn't be a problem. If you are worried at all, you can rinse your nostrils out with eyedrops (saline solution) or warm water so that coke particles don't stay in your nostrils for very long to irritate them. Just flush out your nostrils with water IMMEDIATELY after snorting a line/some lines. I also suggest alternating between nostrils (just as you would rotate injection sites if you IVed), so that you don't put all the stress on one particular nostril.