I believe the poster you are talking about is comparing it to when you accidentally shoot liquid out your nose. Like when you are drinking something and laugh, and the fluid is forced out through your nose.
And Im agreeing with you,thats why I compare the white crust in the nose as the calcium like the booger in the nose as milk,which is not the truth,im using the poster theory to explain that should not be in the case with dusting calcium causing white crust,as milk in the nose that DOESN'T cause in booger formation,hope this is a clear explanation to u.