"WHITE POWDER"

Stuff that absorbs water is like a sponge it has no science other than that. A sponge, or absorbent beads, or foam? Just a wild shot at keeping himidity stable, use it and rub the Buddhas belly, knock on wood and throw salt over your shoulder and hope it works. Seems like you are lucky so far you must have a humidor shrine where you burn incense. Now try the science - put up a hanging humidity device (because moisture falls because of gravity) and use Propylene glycol every 6 months to control mold and put in distilled water every month. Put 1 or 2 Boveda 72% devices on top of your cigars or layered in to complete the science of keeping cigars fresh. The science 10,000 of my customers use to keep their cigars fresh. I get only positives on this scenario.

Mike

The white powder is the same product used in humidity beads and other new types of non-standard humidifiers. It is a synthetic chemical used to release humidity at 70%. If it's free then take it and use it. Otherwise don't spend your money. You're better off using humidor solution once every 3 months or so. A word of warning is that you never allow the powder, bead or humidor solution to come in direct contact with your humidor's cedar interior. It will stain it with a water mark.