Unplug your grinder before cleaning to avoid accidentally turning it on while your fingers or cleaning implements are inside. Bits of coffee ground will build up around the working parts of any type of grinder, slowing them down and potentially adding off-flavors to your espresso grounds. If you notice these effects or see pockets of encrusted coffee ground, use a vacuum's wand attachment or a can of compressed air to remove them. Dislodge larger pockets with a spoon if they are not moving.
Unplug the grinder before cleaning to avoid injury. Use a vacuum or compressed air to get rid of coffee grit when it builds up.