Now careful with the bagging thing...
My husbands pour all the trash from his drawers and car into a trash bag and tells me he will take care of it later. One day I looked into one of the closets and found 3 full bags of papers and "things" for lack of a better word. I asked him nicely to clean it several times until I dumped the 3 full bags (which happened to have a few important documents). He got the point although I must confess I think I went a little bit too far on that one but had fun in the process :).
The trash bag method do work only if you DO DISPOSE of what needs to be put away. Putting things in bags and place it somewhere is like cleaning his stuff. It won't do a thing. Let him miss his favorite shirt and when he ask you where it is tell him you trashed it cause he did not put it away :p :D. He won't be happy but hey... he was warned.