I think the alternative project is a great idea, it should be a Honeypot essentially. Something that nobody maintains or looks at, maybe just accepting all contributions no matter how retarded.

Now you've successfully mitigated them

As an extra aside you can add a contributors guidelines there that contributions explicitly accepts the privacy notice, and then write in it that you will continuously subscribe all authors to all spam lists you can find and will publish SEO optimizees articles about them how they're a danger for employment etc