Severn Trent freebies

I received my hippo bag, yesterday, but somewhere also have one of the old freebies which was a container that you fill with water.


It doesn't achieve anything that putting a non-floating object (eg brick, solid rubber balls or the old freebie) in the tank would not achieve. In fact it's probably (slightly) less economical as an object means that the 'filled' tank holds less, so your dissolving cistern block should last longer.