An all purpose chlorine based cleaner/steriliser which is probably one of the best known and widely used cleaners in the Home brewing world. This is the 100gm tub.
1-2 teaspoons dissolved in 1 gallon of warm water will clean all your homebrewing equipment in around 10 minutes. VWP also has hundreds of uses in the home and can be used to clean flasks, teapots, coffee pots, worktops, chopping boards, dishclothes and can even be used in your dishwasher to sterilise it and leave glassware sparkling.
It WILL release a chlorine based gas and care should be taken not to inhale it when you first add it to your water.