so two nights ago, when my brother and i were in paris, he received an angry phonecall at about 3 am local time from his very irate landlady (their chapter rents what constitutes their chapter house from her). this lady is neither a very nice individual, and is prone to exaggeration (among other things in the course of her phone call she swore that my brother's floor smells "like puke." it does not). She was livid at the state of the house, and proceeded to yell at him for 15 minutes (despite knowing he was overseas

), then proceeded to call all the other brothers leasing a room from her. Basically, though she is overreacting, the fear is that if they do not placate her, they could be in danger of losing the lease and thus, their house.
But here's the real problem: my brother vented to me that although he and another brother try and keep the house clean, others do not. Dishes are left in the sinks. Rooms stink because their occupants never leave them, and in one case, no window exists to air things out. Some members keep their rooms immaculate but do not bother to keep the common spaces clean. The kitchen is a mess because dishes pile up and because brothers who are living in the house over the summer but who have taken off for a bit didn't bother to clean up before leaving.
He realizes they need some way to enforce each member's responsibilities for keeping the house clean, so I suggested having a contract between the brothers stating obligations and consequences for failing to fulfill assigned chores (whether on a rotating weekly basis or every man for himself).
Do you all (particularly the men on this board) have advice on how to make a group of 20 year old guys keep a house clean?