When my DS was young his bedroom was full, and I mean FULL, of rubbish. I could barely get in there. He kept everything - even bits of packaging -anything. Now he lives in a beautiful immaculate property. So there is hope.
Is this your son or grandson, MissAdventure? How old is he? You need to teach him NOW!! Don't pick up after him. He must learn the hard way, if necessary. If he conforms and is good, reward him, if he is lazy, ignore him and leave his mess until he realises that if he needs something it's up to him to put it in the right place at the right time. He'll learn! My son did.
sounds familiar ,my 16 year old GS has a room that would make a pigsty look good.In his defence he helps care for his sick mum ,look after his sisters, works part time in a local cafe and goes to school .His stepdad goes nuts about the room but I sneak in and tidy it when SD is away working . Pick your fights ,a messy room isn't that important in the scheme of things there are far more important things to worry about .I'd just shut the door on it and ignore it.One day he'll realise its nicer to be in a clean and tidy space .
Cure would be no dinner, no clean clothes and electronics unplugged. I'm not sure how old this little boy is, or your relationship to him, but all children need to learn to pick up after themselves and help around the house.