USING the tool.
Choose UK, US, Canada. Areas. Thats the majority of the advertisers/sites/money.
Go through every single page you have.
If you find an advertiser that has a site with any ads or aff. links at all then generally they are buying traffic from you and getting more in return from the SAME advertisers that are on your site. They represent an extra layer so ban them.
Plus... Legit genuine advertisers have a real tangible product or service to sell. And usually a telephone number prominently displayed. No number? Ban them. No product? Ban them.
This procedure has upped my income by over a third, while giving my visitors a better exoperience so they return, and given adsense a higher credibility at the same time meaning better future income and clicks as confidence returns!
And advertisers hate mfas too! So they bid less or switch off the content network because of them. So you do everyone a favour.
When you find one (and you will!) in the tool, do this:
Tick the "show url" box.
Use only the widget.com part.
Dont use www, or http, or anything after the .com bit!
Copy and paste this into the filter.
Once the filters full you are buggered! Email google, explain your problem. They will send you an email saying that they are looking at better tools or larger filter.
Think of it like this. If all your ads were mfa then where would the income be comming from?
Only advertisers that have a real product or service are adding money into the system. All other sites are taking this. Why allow mfas to ruin the publics confidence in adsense, and your own site, by allowing these sites to take the advertisers budget? REAL content sites should be doing that!