The earliest date I can find for the Wikeham Weed Eradicator is an 1894 advert with the item on sale at a florist/garden shop in Royal Avenue, Dublin.
Then there is a newspaper article from 1904 stating “An implement destroying weeds in lawns called the Wikeham Weed Eradicator is manufactured by the Killet Chemical Company, Liverpool. It is a tubular, 36″ long staff, fitted with a self-acting valve, and when filled with a reliable weed killer then simply by pressing the point into the plant enough liquid is injected to destroy it. The weeds turn brown about the second day, and by the fifth day shrivel up and die.”
I cannot find any reference to the fantastically named Killet Chemical Company so it may have been a marketing name. However there is a chemical company of the same time in Liverpool that made insecticides, sheep dip, and weedkillers which heavily relied on arsenic…..
Regarding the Mysto which is obviously the same: There is a 1927 Australian newspaper article saying that a Melbourne horticultural firm stocks the Mysto Weed Eradicator. Stating it’s a tool working on the syringe principle, it holds the chemical and has a pointed end which pierces the stump before injecting the weed killer.
Having looked at a few things it’s probable that Wikeham and Killet were brand names of Mysto. Any thoughts?