If you backdate your post a decade or two you'd be on the right track. But not today. Boveda packs, Heartfelt beads (HF), or silica kitty litter (KL) are the way to go in the modern age. These are all two-way media; meaning they can both increase and decrease humidity to a predetermined RH.
IMO, Bovedas are your best bet for smaller humidors and even larger desktops. HF beads and KL are fairly interchangeable, and are best suited to large cabinets and wineadors. They're most efficient when spread out in a tray about 1" deep, so vertical units like those mentioned are good candidates for this approach, though you can use them packed into a mesh holder like aquarium filter bags or women's' stockings when a tray is not possible. HF and KL require occasional spritzing, while Bovedas must be replaced when used up, though they can be recharged in a separate container.
Like traditional foam & PG, water beads simply pump out humidity and require careful balancing against leakage in wooden humidors - difficult at best; impossible for many inexperienced cigarists. In sealed storage such as tupperdors they simply create the cigar equivalent of a steam room since they have no mechanism for lowering RH when necessary.
Electronic humidifiers may be viable in large cabinets, but still have their drawbacks. Few are reliable enough to be favored by all but a few of us here. And they're still strictly one-way humidifiers, regardless of the the marketing hype that would try to convince you otherwise. Most commercial brands aimed at consumers do have an RH setting, but it only amounts to an automatic on/off switch. If that fails you're back to creating a steam room for your cigars. And once your RH runs over they have no way of bringing it down other than waiting for leakage from the humidor itself to correct it.
I smoke in moderation. Only one cigar at a time. - Mark Twain