I have no idea how this happened but we had SD13 and SS10 this weekend and there were Please and Thank You's flying out of their mouths left and right. They picked up after themselves, asked if they could help in the kitchen, and only had to be told once to do/not do things. I think my DH picked up the wrong kids.
I have mostly disengaged, didn't attend sporting events, don't respond to text messages (I let DH do it) and let DH do all the arranging of schedules, cooking, cleaning and discipline when they are here. Even DH didn't lose his temper and both skids gave me hugs.
So, does this mean that all the effort and resulting anger was a big waste of time and the key is to do nothing at all? Seems to be working for me!