I would probably be a little insulted if asked to do that...I always wipe my feet, then check my shoes before entering anywhere (my home, the homes of others...anywhere) and willingly remove them if they're at all dirty. I think most adults can be expected to do that without instruction. I hate taking shoes on and off though, and to be asked to do that is just annoying to me. (I hate shoes in general, but wearing them outside is a requirement, if it wasn't, I'd be barefoot too.) Kids...well that's a little tough too, because if they're with their parents...Using me as an example (don't have kids, but whatever) it would sound like, "Courtney, could you get little Billy to take his shoes off?" or just to ask him in front of me...seems like it would be a little awkward. With a big group of kids there...that seems simple, easy, and understandable. Otherwise, I'd probably say it's not the best idea, but it is your house.