This is not supposed to be a witch hunt and by the looks of it there is no definitive answer.
My only question to manufacturers is that in the search for ever heavier marking paints has the principle that the players wish to use their tops more than once fallen by the wayside.
I use in excess of 15,000,000 balls on my sites and never have a problem with our laundry contractor. There is obviously a difference between the so called cheaper "site" paints anbd tournament grade.
I know everyone will get on their high horse but "if players walked when they got shot why do we need such staining paints"
All I ask is if in doubt take your paint back to your supplier and quote trading standards saying it is not fit for the job is has been sold