I can't understand why anyone would advise you to refuse to have a water meter installed. You'll almost certainly save money, which is good for you, and you' ll use less water, which is good for everyone.
Quickbeam. Some tinned tomato's have a higher water content than others!
I also think the showering idea is one of the best, providing it is short. Even better if you turn off the water whilst soaping up and lathering all over then turn the water back on rinse off and you will probably have used less than a couple of sinkfulls.