i am using them. i like them and they work great. i put some in a month ago and it weighs the exact same and smells great and seems to be perfectly curing.
i ordered a few different ones and one size came messed up, i emailed and they called and had me a replacement in a couple days. he gladly spoke with me on specifics, it was great.
i did it as it said on the site, i dried, sweated then bagged. they have a ziplock so you dont have to heat seal it although you can.
overall i am pleased and will buy more as needed.
at first i used a gauge and checked the humidity but found it to be spot on.
i use a moisture meter and it seems to do the trick. im very happy with them!
...and... i put an avocado in one and i was pleasantly surprised that it didnt turn at all!