First, are you sure it's the vent and not the umbilicus that is drying up and crusty? Seeping sounds like the umbilicus not the vent. If so, don't mess with that at all other than, if you want, dap a bit of iodine on it. The vent needs to be kept clear and do not put molasses in the water. That will give it diarrhea and make things worse. Find unfiltered Apple cider vinegar with "the mother" (sediment) in it, add a couple teaspoons to a quart (not in metal waterer, only plastic). That helps with pasty butt. If you wash off the vent, dap a bit of vaseline on it and it will keep poop from sticking, but make sure you're looking at the vent and not the umbilical stump. Always, plain yogurt, never flavored--that has sugar or artificial sweetener in it. Put a couple of tablespoons in a bowl and sprinkle some crumble on it and they'll eat it.