I completed the top one and it was a ton of work, can anyone comment on the effectiveness of actually doing all this?
As commented above, the companies are required by the Fair Credit Report Acting Act abide by the requests. [1]
[1] https://www.consumer.ftc.gov/articles/pdf-0096-fair-credit-r...
The do-not-call has been fantastically ineffective for me. I imagine this could be the same. It's also possible that all of the companies strictly adhering to the FTC rules (i.e. those on the OP site) constitute a minority of the market, and spammers are getting data from other less scrupulous sources.