Is there a trick to exterminate earwigs?

Earwigs are mostly a damp problem. Clear mulch, leaf piles and boards away from the walls, fix any dripping taps or downpipes, and they lose interest. The cheap trap that works: a shallow tin with a bit of soy sauce and vegetable oil, sunk to the rim. Or a rolled-up damp newspaper left out overnight - they hide in it, and in the morning you bin it. Diatomaceous earth along entry points if they're coming indoors.