many thanks Aunt Sally, the sodium chlorate and red (for danger) watering can have been duly returned to Wilkos. i think i should stick to my organic and enviromently friendly morality in "all" my gardens. i knew it was a good idea to ask here before i did anything drastic.
i'm going to use the old manual weed killing techinque of cutting, digging and pulling.
Princey says thank you too!
Laura
p.s. i swapped the chemicals for some red hammerite paint to spruce up the fabulous manual lawn mower (Qualcast Panther) that i got from freecycle