So you toss the Laundry Lump in with your dirty clothes, and "Wow!, look at all the suds!"
(Which we here know are the suds from the detergent left over in your fabrics that didn't all come out in the rinse cycle.)
And after the last of the detergent has been washed & rinsed away in a few more such cycles, water, by itself, does have some cleaning ability.
Months later, when the cleaning ability of water alone can't overcome the buildup of daily gray:
"Gee whiz, dear, this Laundry Lump doesn't seem to be working any more. I think it must have worn out or something. Time to order another one...."