Usually, whenever celebrities advocate some cooky thing that supposedly does a whole lot of good, it’s just a trend or a cooky idea — but Cameron Diaz is really on to something here: she wants you to stop flushing every time after you pee.

Every flush takes somewhere between 4 and 10 liters of water – and most of the time, that’s not really necessary; huge water quantities are wasted this way, and if you want to be more eco-friendly in the rest-room, there’a simple rule you can follow: “If it’s brown flush it down, but if it’s yellow let it mellow“. It’s definitely not the prettiest thing out there, but it really goes a long way (though may want to bypass this rule when having company).

Another thing that really works is what the Hollywood celebrity suggested – urinating in the shower. Ok, this is gross and you could never do a thing like this, but here are the facts: 42 percent of all Americans urinate in the shower, and other countries do it just as much; men do it, women do it, kids definitely do it, and again, this goes a long way to preserving quantities of water which would otherwise just be wasted. Diaz also advocates urinating outdoors, but this is definitely not an option 99% of the cases; still, it’s something to keep in mind when you’re outdooring.

Other small useful things you can do is turn the water off when soaping your hands and washing your teeth, and using faucets and showerheads with aerators; they use only half the the water flow with twice the power. If they were used nationwide in the US, we could save 250 million gallons of water a year.