How do you recharge them?
According to the name these use Bentonite clay as their absorbing material. They recharge in the oven and the other side of the bag likely has the temp and time required.
Clay are limited to 5 time recharge.
Also, according to the model these bags are going to be medium small even though his picture is huge. They are able to absorb roughly 1 oz of water before recharge needed according to the specs.
