Why would they go to great pains to locate a sale when they had timed, dated receipts?
That a sale of bleach was made to somebody or other (let's assume there is evidence for that although I would like to see it) is not the same thing at all as a sale to Knox or Sollecito. The bleach receipts were said to have been found in Sollecito's apartment. That is the evidence in which you have claimed to believe along with the idea that it was not used because, well, they don't use everything, do they.
Let's just hasten to add that in addition to a "bleach receipt" not existing, it is one more idiotic meme of the police and Mignini to claim such a fictional document would have any relevance.
There was no bleach clean-up, nor would one be scientifically possible, so as to account for the absence of evidence against anyone but Rudy Guede.
The footprints revealed by luminol, in addition to only Rudy's footprints made in wet blood, show there was no "bleach clean-up", nor could any "bleach clean-up" selectively clean-up only Rudy's DNA, only Rudy's fingerprints in wet blood, Rudy's palm print, etc.
The meme of a "clean-up" is meant to counter the bald absence of any proof of anyone but Guede at the crime scene, and for whom there is vast quantities of such physical evidence for only Rudy Guede.
Just as the "stage break-in", is the Italian police's idiotic meme to explain away the obvious conclusion that the break-in was not staged and simply committed by Rudy as part of his normal burglary procedure, these are idiotic digressions, that the Italian police apparently feel the Italian media is idiotic enough to report, and the Italian public is sufficiently idiotic to believe.
That such foolishness was reported at all is a tragedy. That such idiocy continues to be bantered around amongst the guilter coven of lunatics, is yet one more argument in favor of China's approach to "re-education camps".
Bleach receipts are a non-starter, because they're irrelevant, and the obvious fabrication of Quintavale and the cub reporter, both of whom belong in jail for their actions in this case.