After the salesperson at my Sears recommended them to me, I am totally sold on them.
I was having problems with that smell that everyone complains about, the mildewy smell and when I was in the store one day, I asked. They told me to run one of these tablets in my washer (a Kenmore HE2 Plus) every month and to also leave the door open after I finish doing laundry and that doing that would help get rid of or prevent the smell.
She was totally right! I started doing that 3 months ago, and the problem is completely gone.
I didn't find that this made any difference once my washer started to develop a musty smell. However, 1/2 cup Borax in every wash load made a world of difference. I can cut my detergent in half and never have any musty smell in my front load Samsung washer.