At my house we’ve been doing all the recommended things to minimize indoor water consumption, but anybody who washes greasy cookware knows you need hot water to help cut the grease. Collecting water in a bucket until the hot water arrives and using it for our planters didn’t satisfy me, though. I considered that running water until it gets hot not only wastes water, but it wastes energy too, because when I’m finished I end up with a bunch of hot water in the plumbing between the heater and the distant kitchen that will just sit there and get cold again.
So. What I do now with greasy cookware is put a cup or so of tap water into the soiled utensil (I can’t see any reason for more than that), squeeze in a little detergent, and put it on the stove with a high flame for about 30 seconds. Then scrub well with brush and sponge (soak first for stubborn debris), and a quick spray with cold water. Must be careful, it’s easy to overheat and risk a burn.
If I had an electric stove I’m not sure I’d like the delay; with gas it’s quick. Anyway, if you need hot water you’re going to use energy to produce it one way or another. This way I’m not heating water that will sit in the pipes and get cold, when it’s often only for one frying pan or broiling pan (unavoidable for baths and showers, though).
Another technique: after dishing out food from the warm/hot cookware, immediately add a little soap and water and let it stand while you’re eating. The water should be nice and warm when you’re done.