So, I got my cooler(dor) prepped and was doing some research on HF beads and KL. My wife saw me on the laptop looking at KL on Amazon and thought I might have lost a few marbles since we don't own a cat. After explaining the purpose of the beads, she told me she saw similar "round thingies" at the craft store that was used in vases to preserve flowers.
I found the product online and the item description seems like it should work. Price online was $7.99 for a liter of these gems but I found them on sale at the store for about $3.00 -- not bad!
Linky ----->
Panacea Clear Water Gems
I put a small amount of these in an open tupperware type container and placed it inside the coolerdor. After about 4-5 hrs, the RH reached about 90%. Looks like they have quite a bit of surface area so I took the lid and put about 6 small holes in it essentially turning it into a big water pillow. That did the job and for this past week, I was able to maintain a constant 70-71% RH.
Obviously, like kitty litter, they require some trial & error to get them to sustain your target humidity level but, thus far, they do seem like they're doing a pretty good job. Only difference may be shape and size. This may be a good psychological alternative to some members here that can't get over the idea of placing kitty litter next to their fine cigars. The price is also extremely affordable as I could imagine that one of these products could take care of a pretty large humidor.
I'm not sure if this type of product has been mentioned here before so I thought to share my findings.