My son was like that, and my DIL was able to change him. She just stopped picking up after him. Yes, she suffered because of the mess; but so did he.

Because he wouldn’t hang up his clothes, she refused to do his wash or iron them.
For weeks they tripped over his huge shoes in the hallway.
She left his filthy dishes in the sink…for weeks! YIKES AND YUCK
No more fresh towels
No more fresh bed sheets
No more underwear…gag!

It goes on and on. I don’t know how she could stand it, but she did, and to this day my son has changed. Infact he’s become neater then my DIL! Hah, if that isn’t a joke.

Within half a year she accomplished something that I was not able to accomplish as a mother. I tip my hat to her.