Well, apparently that used to be the official advice er and, and we were correct in that but the authorities have now changed their minds and they no longer want us to pour waste chemical down the drains and I gather that the official advice now is that surplus diluted chemical should be poured, and I'm quoting here,on to more or less level and bare soil in the garden or on to level gravelled paths, avoid disposal in areas around ponds, erm water courses and so forth, dishes and, and what have you  and as far as undiluted chemicals are concerned, that's stuff still in the bottle, the advice there is to talk to your local authority cos they have different regulations in different areas.