[Acrylic-bob]

No one is giving anyone 20p. A deposit is an additional charge for the use of the bottle, which is held by the retailer against return. Don't return the bottle, don't collect your 20p. What happens after the bottles are returned is actually immaterial. Smash em and melt em down or reuse them. Though I do accept that bottles filled with oil or whatever else can be a bit of a waste of time if you are going to reuse them. But then surely it is up to the retailer to make sure that he or she does not accept bottles that are obviously contaminated. And from an environmental viewpoint it makes much more sense to use the billions of tons of glass that is already in circulation than constantly using up virgin resources.