I haven't seen them in years and believe me, I've looked. The last places reported were Target and Eckerds (now CVS). I know Wisk, Tide and Purex made them at one point. Apparently one of those marketing schemes, that are similar to Avon or Mary Kay but for household items, had them the latest. Maybe someone else will know more. We've started hoarding the boxes using liquid when we have the opportunity. I did a good search and didn't find too much.
Would that be Amway you are talking about Dean? Not really a marketing scheme as they have been around for many years(HQ in Grand Rapids, MI, DeVos family ownes or used to own it(who knows with all that private equity activity anymore).
Yes it is kind of a Avon/Mary Kay operation for household products. I just looked it up SA8 is one of their home product lines and it looks like they have tablets(picture of product line).