I'd agree that it's an unusual phrase - it's certainly not an idiom in common use. It's obvious from the context what it means, though. As Gary says, maybe to sweep away all the stuff that's getting in the way - making the floor clean so that you can see clearly?

It seems an odd phrase to me. It's certainly not common. I had to look up the source to get more context to understand it. I think that it means to ask them to 'get out their brooms' and 'sweep away the cobwebs' that may be confusing you. i.e. by sweeping away the mess, they may help you to see things more clearly. I hope this helps, or at least puts it in context.