My children are hoarders. Here's a sampling of things they collect and refuse to throw away:
receipts from the grocery store
empty spools from thread
dried out play doh
clothes that are too small for them and yet too big for stuffed animals
My plan is always to wait until they are at Daddy's house then ditch their crap but I always forget. When they catch me trying to toss stuff out I cave to their tears and let them pull whatever sacred item it is out of the trash. I suck at being the tough guy with things that really aren't threatening to a person, a piece of furniture or window. (After Big Pants broke the picture window with his bottom a few years back, I learned to yell quite loudly in defense of inanimate objects I don't want to replace.)
A friend came over and after looking at my house they suggested instead of cleaning it my best course of action would be to move away and start over with a clean slate. This seems brilliant. My new plan is to pack up their things so that things can be strategically "lost" by movers. When we get to the as-yet-unpurchased home they can play in the empty boxes, which is actually all they really need.