Generally speaking I use as little chemical spray as possible but have resorted to a product recommended to me, called (here anyway) Ripcord. It is a spray for application to buildings to stop spider infestation with their webs and filthy droppings. Spiders really are dirty creatures. Anyway, I use it in my plant trays and on benches, around pots, against slaters and it works totally. Slaters don't come into the trays at all where before they were clustering in thousands in every corner. It can also be squirted onto plants with no ill effect to the plants, against slaters and aphis. I found that be accident, having sprayed a bench where I was setting out seed pots and next morning found dead aphis from the adjacent auriculas.
Recently following a lot of rain, slaters have been coming up the house walls and coming in through the bathroom window. Some mornings there have been a dozen in the basin! Not nice. So I've squirted the outside walls and the windowsills as well. Slaters still coming in but they die when they get there so we now have dead slaters in the bathroom instead of live ones.