Hi dog-tired,
I urge you to go out and buy Fito 'Slug Stoppa Tape', sold at ironmongers, DIY and garden centres. It is an adhesive copper tape, that acts as a barrier on tables, chairs, pots, staging and greenhouses. I have a prized Hosta plant, now in a large pot - originally in the ground - which is haut� cuisine to slugs and snails. The copper tape gives either of these slimy creatures a mild 'electric' shock when they cross over it. So successful is it, that my Hosta has not one leaf chewed, bitten or slimed on! There are trails of them everywhere else, but none on the planter. Have used this tape on other pots for 4 - 5 years now, and only needed to replace/refresh once.
Environmentally friendly - well to us - not the slugs !!