Things you need:
- Medicine Bottle (child-proof type)
- Coffee Filters (the flat, cone type)
- Crystal Kitty Litter
- Ice Pick or Drill
- Punch holes in the cap of the medicine bottle
- Trace the top of the bottle onto the coffee filter and cut out the circle
- Put the coffee filter into the cap
- Put a couple of plastic spoonfuls of Crystal Cat LItter (silica gel dessicant) into the bottle
- Close the bottle and put in storage container like camera bag, gun case, etc.