Fascinating. I just assumed Heartfelt
manufactured them to work the way they do. I can't imagine why this stopped being talked about, since beads are the second most recommended product after Boveda packs for humidity control.
After reading this, I'm pretty more convinced that RH Shield are the same as Heartfelt, mine are working fine. However, two pounds of your beads,
@CigarStone cost $13.
One pound of RH Shield beads cost $49.

Talk about compelling economics! If yours are still working after 15 years, I'm a believer!
I have several Xikar Humifan units, and a spare 5L Sistema container. If I understand the process, use normal humidor seasoning techniques to get them close to 65%, then remove the seasoning item, and pack them with Bovedas for a month? I gotta try this.
I wonder how the hell this fell out of common cigar community conversation? The number of YouTube videos on calibrating hygrometers or recharging Boveda packs is redonkulous.
Edit: Some further Googling indicates that things like Heartfelt beads, and probably RH Shield beads may have silica beads manafactured with salts to work best at a particular RH. But I'm going to take Cigarstone's 15 years experience and try this. Thanks much for the explanation!