My office hovers around 50%rH, I put in plenty of litter, sprayed it lightly (about 40-50% wet) and it holds at 65%rH like magic. I'd swear this stuff was designed for humidors. Even with winter approaching the rH doesn't change significantly in the house here in North Texas. We'll see what happens but I don't expect much to change.
As a side note, try mentioning kitty litter on some of those *other* places on the internet! They all swear you're crazy! Talk about a flame war! The bottom line is, just try it! If you watch your hygro until you are convinced then you have nothing to lose but $10 for 10lbs of litter. Compare that to the $32/lb for the beads! I'm sure the beads work and are a great product specially made for the purpose, but I swear to you that the litter does too.
Remember, we aren't talking about the gravel type gray rocks that you automatically think of with kitty litter. These are white and opaque, just like the other stuff. It honestly looks nothing like kitty litter. Just call it gel and nobody knows the difference.