Forty pence, which is a small saving and a real bottle
The saving
Forty pence per refill against buying a new bottle. Over a year of monthly refills that is under five pounds.
The packaging
One bottle instead of twelve. That is the part worth doing and we would rather say so than inflate the money.
How it works
Bring any clean bottle of ours, or one of anybody else's the same size. We do not check whose it was.
