I actually don't recharge mine. I did that one time in the washer and what a bitch. It did make it smell "new" again, you know that carbon type smell. But it took so long to get back to form and I had to cut it open to do it.
I was having problems with mine at first also. I was using a blower and pulling through the odor sok and just exhausting out the duct of the fan. I found out that my blower sucks air not only from the intake duct, but also from the part of the fan that has a grate over it. So when I was pulling the air through my odor sok, it was only pulling some of the air through the sok and the rest through the other part of the fan. I have since changed it to blow through the odor sok and that fixed the problems.
These things are not 100% by any means. They don't work as well as a real carbon filter, but in my experience, they cut the smell by like 80%. I don't mind a little bit of smell. I exhaust directly outside, and don't have any problems. I live in an apt complex and you can't really smell it at all. Before I got the Odor Sok, you could smell my grow like a block away. But now, its only if you walk in my spare room, or during the last week or 2 of flower.
For someone that just needs some sort of odor control, and donesn't have a ton of money to throw around, I would suggest an odor sok. However, if you are looking for 100% odor reduction, I would suggest an actual activated carbon filter.