I just want to give you guys a headsup about a potential problem with the water pillows.
I have one that I've kept in my wetbox as a short term humidification device. I went and checked on it a few days ago and smelled an unfresh odor. I traced it to something that looked like mold or bacterial growth inside the pillow. Now, I have handled the pillow and do not take pains to keep it sterile and so I suspect it just picked something up and it started to grow.
As a result, I don't think I can recommend water pillows for extended use and certainly not for reuse. Exposure to the environmnent and fingers and stuff seems to be enough to allow bugs to hop into the gel medium and start snacking.
I think they are fine for one time use traveling with a pass or for temporary adjustments but I would not let them dry out and then try to rehydrate them.
BTW, my wetbox is a tight-sealing tupper where I store Boveda packs, Fuente humi packs and PG solution tubs. I take them out as needed. I think everything else is ok and that the odor was confined to the pillow which I have now trashed.
Wilkey