Just got off the phone with an arts & crafts shop and they can supply me with a jar of reusable silica.
Incidently,I had called them yesterday about "storing my old cameras" and they didn"t have a solution. When I phoned today I said that photography was now a thing of the past and I wanted to take up drying & pressing wild flowers. Guess it was all in the wording.

Thanks All,
Mike