"Larry Stoter" wrote in message
...
Roger Tonkin wrote:

Snip

So it looks as if it must be a chemical attack, but
what with? I,m hoping to get to a garden centre next
week, so I'd like some idea of what has worked and
what to avoid if possible.

Many thanks

Have a go with coca-cola - seriously.

Full strength coke is a good, cheap and easily obtainable cleaning
agent. Personally, I've used it for removing oil stains from concrete
which it does very effectively.

... which is why I can not understand anybody putting the stuff inside
themselves ...

I know of a number of garages who use coca cola for cleaning
battery terminals!

Phil