Sandy soil

Where I am located in Mi. we have a lot of dry sandy soil, I use Steve A. traps when setting I push in as far as possible, so the winding spring is inside the tunnel. Outside of wetting the soil how do you keep the dry soil from running back into the tunnel and behind the trigger/pan?

Wetting the soil is a great way o get moles up to the surface. I'd be using no moles in sandy soil though.