Product review (2 stars): I found a better alternative to BestAir
I have used this product now for about three weeks in my wicking dehumidifier.  It doesn't work well.  I put in a capful per gallon, just as the instructions say.  When it wasn't working, I added even more.  No dice.

My wife said, "what's that smell.  Like a rotten sock."  It's the dehumidifier.  A new, two month old dehumidifier.  This BestAir stuff is expensive and simply not the best for treating the sitting water in devices that involve water reservoirs.

What does work?  Bleach.  I got a one dollar bottle of plain household bleach at a dollar store, and keep it in the cabinet underneath the utility room sink where I refill the bucket (and carry it to the dehumidifier).  I put in a teensy amount of bleach... less than a capful for three gallons of water (I was adding three capfuls of BestAir!).  Barely enough to smell it (not enough to make my dehumidifier smell like a swimming pool, not enough to degrade the wick in the machine), and--Voila!--smell completely gone.  Instantly.  The dehumidifier smells clean and new again.  Slightly pool-watery, but only if I use too much.  Honestly, the one dollar, gallon bottle of bleach will likely last me a year or more.

I;m very familiar with the detrimental effects of bleach on wicks,, cloth, even plastic, over time (swimming pool owner).  The key is to use very little (a few drops) and to replace the wick in the machine every six months or so, regardless.  It'll be keen. And I'm not "breathing bleach" anywhere near as much as someone doing laundry or swimming in a pool all summer.  Again, add just so much that you can't even smell it.  It takes, literally, drops.

Obviously, don;t spill bleach on the carpet.  But, by same token, I wouldn't spill BestAir, either.

So, I found a better, vintage "mousetrap": household bleach.