How to remove a Google "pure spam" penalty - this works!

How to remove a google spam penalty warning? Recently we bought an expired domain with a decent DA - not great, but OK. We built a new site and wrote about 100 articles for it. Pretty quick, simple answers to common questions. It's not exactly unique, it's a little bit too broad and not specific... but it's also a fine site.

However, the expired domain we bought had a flag warning on it. I knew this from using DomCop, but I didn't think it was a big deal. There's a little orange explanation point warning "this site has been flagged as a spammy domain." I didn't realize how hard that would be to get rid of.

We built the site and submitted it for reconsideration, but it was rejected (without explanation).

I did some research.

I changed a few of the header and footer links that were going back to designer.

I got rid of all ipsum lorem default text. 

I added some cool tools to make it more fun and sticky.

Still rejected.

I added a contact page, form, privacy policy, terms of use.

Still rejected.

This time we investigated all our spammy backlinks and officially disavowed them.

That didn't help, either.

We provided ownership and transfer of the site.

We have a "pure spam" warning but no spam and at this point, we don't know what to do. I think, probably, Google just wants to wait and see how things turn out. After all we could make a clean website and get approved, and then just change it all. It makes sense they'd be reluctant. 

So probably we'll start building backlinks from reputable sites and try again later...

But what if there was a faster way?

As a case study/experiment, I'd like to try using Google ads. I'd choose the least commercial topics, that are helpful without being easily monitized; that way I can probably get very cheap clicks for very specific, common questions - to "train" Google that this is good content and let them see real people clicking on and engaging with the new site (I could also buy traffic or boughts but that's dodgy on an already dodgy site). 

I could also focus on driving organic traffic in other ways too; like comments or forum posts or links; answers pointing back to our full answer on the site. But that would require being present and thoughtful - I don't have time for that.

In theory, if I can get cheap clicks for 0.03 cents, then I could get about 100 real visitors a day for $3. 
That's about $100 a month, for 3000 visitors... not bad, and if they behave like organic visitors it'll probably help us rank - especially for the exact keyword matches they were searching for.

So the trick here would be using noncompetitive keywords to get cheap uncommercial traffic in order to override Google's own safety protocals (they might not, but I suspect they'll take our money through the ads dashboard). We can keep this traffic going to give Google data, so that they can make a reasonable choice. Right now they are making an unreasonable choice, but with a lack of data it's best to err on the side of caution, so I get that.

What's the fastest way to send data to Google? Buy traffic... with its own ad system. Probably.

What do you think?

UPDATE (it worked)

I actually forgot I turned these ads on, so I spent about $700 bucks. But we noticed a few weeks ago that the site was listed in Google search results again. We didn't get another warning and didn't try to submit the site again with new evidence or arguments. It just started ranking. I can't *prove* this was only due to the ads, but I had tried everything else and gotten a firm no.

I suspected leaving it to run clean for awhile and eventually Google would pick it back up, but I'm pretty confident the ads helped. I'll test it again on another site that's also blacklisted.