Then whenever someone is accused of having dirty coins, they can pull up a screenshot of this site and it will be 'word against word'.

This is not a bad idea, especially when we consider that many entities which buy in to taint analysis do not have the slightest clue as to how taint analysis actually works or how the whole thing is (bad) guesswork.
Even better if you can add some history: "parts of these funds were mined in the years 2012, 2014 and 2018". All 100% clean, of course

Either that or go the other way to highlight the stupidity of the whole thing. "Approximately 2% of the coins in this output were once used in a casino, and have transacted through 592 addresses in over 10 years since then!"
I'm all for adding more information, as long as it's legit like '100% comes from miners' and such; funny, informative, making the page a bit fuller and more similar to previous 'taint analysis sites', and - most importantly -
true. This is what should set this site apart from all the previous ones. 100% undebateable truth and facts, opposed to empty speculations and accusations.
Top-level domain name recommendations:
- taintobjective.ly
- tainted-defac.to
- coinri.sk
taintanalys.is is available for registration.

All sound pretty good to me! Are the previous three available, too?
Honestly, what started as a joke might actually be a very good idea to implement..

Even if just to stand against all that other bullshit that's floating around.
Unfortunately, I'm not a big web developer, but I could try my luck throwing something together and putting it on GitHub for someone to host, if nobody else has the time.