Humidors keep cigars at the perfect RH essentially forever. Optimal RH for stash is somewhat lower (50-60%). Here's what you would need: Humidor, hygrometer (to measure RH levels), crystal humidifier, propylene glycol (or distilled H2o). The idea is to reduce some of the moisture that the crystals emit, therefore lowering the RH to desired levels. Placing some tape over the holes in the crystal humidifier would seem to reduce output to reach the 50-60% sweet spot. This method should keep cured stash perfect for years.