The much-publicised campaign to get Britons back into the kitchen instead of paying for expensive and waste-producing lunches has been put to the test.Writing in the Telegraph, Becky Pugh has followed the advice of the governments Wrap initiative and replaced her daily trips to the sandwich shop with a packed lunch in an effort to save money and lower both the food and packaging being wasted.For five days she made her own sandwiches in her kitchen at home and then reflected on how much she had saved.Ms Pugh said If my calculations are correct, this [saving] is the equivalent of 3.30 a day.Hardly tuppence hapenny, but a savings a saving in these straightened times.While taking packed lunches to work can have green benefits, installing a filter system into kitchen sink plumbing can deliver filtered tap water on demand, reducing the water wastage that can sometimes occur with a separate jug system.