. . offering to help see that reviews "helped my business". I declined, telling them I'm trying to shut down this business and am not interested in any publicity.

Especially when you see a bunch of bad reviews accompanied by a batch of really good reviews, and not much in between, you can be pretty sure the good ones are fake.

I saw one that promised "top ranking on Google" that was getting really bad reviews. The owner asked everyone he knew to post a really good review. He gave them an example to work from. Every one of them just copied the example. Not a really effective campaign.