If anyone has been searching for this chemical which is the active
ingredient in "ivy Killer" and "Root Out". It can still be bought on
ebay in either 2lb or 5lb quantities. Just search for "ammonium sulphamate"
Of course you must not use it as a herbicide according to Nanny EU but
still OK to use as a composting accelerator as long as you are careful
not spill any on any unwanted ivy, horsetail or tree stumps on your way
between shed and compost heap.

Usual disclaimer: No commercial connection with the seller apart from as
a satisfied customer.

Bob