Not done it myself but mustard and pork is a great one.
Found this that i had held for a few years. Makes a great dipping one. Dunno about glazing with it. But im sure it will do the jobb if done the last 10 min,.
Mustard Vinegar Sauce
1 cup apple cider vinegar
1/2 cup Yellow mustard
1/4 cup onion finely minced
2 cloves garlic pureed
1/2 teaspoon black pepper
1 tablespoon Worcestershire sauce
1/2 cup brown sugar
1/4 teaspoon cayenne pepper
1/2 teaspoon salt
1/2 teaspoon Tabasco sauce
Combine ingredients and simmer for 15 minutes, stirring occasionally.
For a smoother sauce, blend on high for a few minutes.
I've never had mustard sauce on ribs, I love it though with PP. There is no reason why a mustard sauce would not work either way, just depends on everybody's taste. Check out Roxy's Mustard Sauce on this and other sites.
I agree with the Roxy Sauce, the stuff can be down right addictive on pulled pork but just one word of warning, do not stick your head over the pan for a sniff. The above recipe is Roxy's