A: Yes, you do. They are formulated to release a steady amount of moisture into the air. They work best with distilled water, but cigar juice will work as well. These ship dry so that you can add water at your own discretion. If you only need to use 2 or 3 pieces, you only have to activate that many. To activate the beads, start off by adding an inch or so of distilled water. Slowly keep adding water, allowing time for the beads to expand in between, until the beads near the top of the lid. Do not allow the beads to expand beyond the top. Maintain as you would a normal humidification device, never allowing the jar to become bone dry or overfilled.
A: Yes, you should use distilled water. You can use cigar juice as well, but distilled water is a cheaper, just as effective route. The length of time in between refills depends on how big your humidor is, and how dry the air may be. On average I would say every 3-4 weeks. Don't ever let the beads dry out completely. Always keep them somewhat wet, as a complete dry out shortens the lifespan of the beads.
A: Slightly longer than the standard Humi-Care line because the crystals are shipped dry. The standard jars come filled and they actually lose a bit of life when they sit in our warehouse. We advertise 12 months, but I've had jars last over 2 years by making sure I use a rotation of distilled water and cigar juice when refilling the crystals. In short, they last 1 year +