Product review (4 stars): Seems to do a good job without and odor.
West Texas is DRY and in the winter we have to use humidification.  We use a large, evaporation unit with foam-like filters.  We deal with mold, bacteria, and hard-water crust.  We normally use chlorine bleach for the first two and a descaler for the third.  All of which have a strong scent, but we thought it a necessary evil.  This one clearly takes care of the bacteria and mold, and does not have a noticeable scent.  The surfactant in this does not solve the hard water crust, but it cuts it back quite a bit and seems to make it easier to clean.  This is solving most of our issues and will definitely extend the life of the wick/filters.