Good point, I often find that if a DC is bothering me during an LD, telling this happens to shut them up quite fast! :3
Other than that, DC’s that show up in your dreams often times represent aspects of yourself, so maybe ask them what they represent about your “inner-self.”
Some of my other experience shows that DC’s can assist in locating dream things (People, items, signs, etc.) I have often been assisted by DC’s in finding some people that I want to meet in my dreams. So if you’re ever having trouble calling, always ask the DC’s!
I so far have never gotten along with my DCs that well. However, I think you should ask them some classic movie quotes.
Here is a list of things to ask, some are adapted from movies, others aren’t.