I haven't been around for ages, but have just read this thread with interest. I have got to say I agree with everything, my 2 (3 and 1) spend all day winding each other up and I can feel like I shout constantly at them.
Actually I had a huge shock recently. Social Services called me up, apparently I had been reported by some busy-body or other. An anonymous caller said that I shouted and swore at my children all the time, they were always crying and that they were worried I was about to lose control. On top of this they complained that I worked full time and had a nanny!
I couldn't believe it, Social Sevices had to call the GP, the nursery and everyone in contact with my kids to check I was not abusing them! Then the woman siad to me that 'shouting at your children does not help, and I need to sit down and discuss rationally the problem, or put them in their rooms!' My reply was that I am jolly well not going to rationalise with an 18 month old as she climbs on a stool (which she has pushed by the cooker) to see what I am cooking, and putting a 3 year old in her room (which I do) creates more noise as she beats her feet against the door and trys to kick it in!
Anyway, it did bring me up short that someone thinks I shout too much, I don't smack (save the odd tap) and I do separate my kids. But sometimes I lose it totally and do scream at them (PMT) I wish there was a realistic alternative, or magic potion that would actually help. Like everyone here I have tried the books, followed the advice, done the star chart, but there is no will greater than two little children who are intent on killing each other!