It's a bit hard to tell if these are getting the job done. I have vacuum sealed containers the plant material can be very dry when I put it in. Perhaps these are better at maintaining a humidity level.. rather than adding needed moisture. I have just put one or two of these in (depending on the amount of plant material) and kind of hoped for the best. I will say they are not doing anything "bad".
I guess they are good Iâ€™ve only had them for about a month but they seem legit