I've tried that technique in the past, and as it is quite easy to find content that you can rewrite in a better way and add few things here and there to make it more readable etc, it's not so easy to get mentioned with only cold-emailing people.
For me, it always has been better, to build some digital things, like ebook, infographic, video to get mentioned and get links from strong domains.
But if you will try to rank in a semi-competitive niche and you will be able to scrap a lot of emails it can work pretty decent.