Sites that expose scam sites include badbitcoin.org and scambitcoin.com. If you're really unsure then make a thread on bitcointalk.
The influx of brainless newbies is so massive, that the few people actually paying attention to these sites are on the very low side. It's not for nothing that genesis mining and a few related garbage holes managed to keep operating for so long. I rather have someone create a list of scam sites and potentially scam sites on Bitcointalk, and then have that thread be stickied on top of the page of the marketplace section by a mod. It will probably have a very small effect, but at least it might translate into less people falling for obvious scams that they see as legit operating 'services', especially with an eye catching clickbait style title, where in this case it isn't clickbait.
It would be nice to have a very visible location on the first page of bitcointalk.org, but how would it be kept up to date without any misleading info? You may have posts that incorrectly identify legitimate projets as scams and vice versa, if it's left up to anybody posting. Having a dedicated team that is on the lookout for such scams with some sort of maker-checker setup to avoid bad postings could potentially work.