Anyone heard of or use one of these?? Wondering if they are effective or not. Product Description Remove moisture in any enclosed space, like your gun cabinet or safe, with Remington'sÂ® Mini-Dehumidifier. Uses colorless, odorless nontoxic Water Glass crystals to constantly absorb moisture from the air. Every 30-60 days, the indicator window will turn pink when the unit needs regeneration. Simply plug it in to a standard electrical outlet for 10-12 hours, and the indicator window will turn blue when it's recharged and ready to go again. The average life span is approximately 10 years.