untidiness

Untidy person does not completely see/aware and fully believe in tidiness and clearness! He does not impatiently care if the objects are in there appropriate places or strangely/oddly all over the dirty floor!
I am tidy and I have a know-how/skill in creating a tidy and clean house, but the obvious question here is my untidy brothers are all older than me! How can I politely make them obey the rule of putting the rubbish in the bin and the house things in their suitable places?
Another question tag: the sloppy person cannot easily be tidy. Can s/he?!