I thought it might be worth a shot to try this site (optoutprescreen.com):
Thank you. Your 5 Year Opt-Out Request has been received. Your request will be completed within 5 days. However, because your name has been provided to businesses that have not yet mailed their pre-approved offer to you, you may continue to receive certain pre-approved offers for several months.
While your name will be removed from the pre-approved credit or insurance offer lists that Equifax, Experian, Innovis and TransUnion provide to businesses, you may continue to receive mail from sources that do not use credit reporting companies to compile their lists.
Emphasis mine, by the way.
The only reasons I picked 5 years and not permanent are that:
- I’m cynical enough to assume that permanent does not work in practice and that my name will eventually end up on their lists again.
- I’m happy with the creditcards that I have right now but may want to see what they’re offering me in a few years, because I assume that the kind of offers I get is vaguely (!) related to my creditscore which, compared to US citizens is very young and as a result not as good as it could be.
The next few weeks/months will tell if the flood will turn into a trickle, at least.