How about a two-tier marketplace:
Tier one: Products that have been reviewed
Tier two: Products awaiting review (along with a note saying USE AT YOUR OWN RISK).
Mind you, all products are basically USE AT YOUR OWN RISK - this will just remind users that they’re using an unvetted product.
They could filter based on whether the product has been vetted or not, so they can see just the vetted products. And the marketplace can use the users ratings of unvetted products to decide which ones to prioritize for review and inclusion in the regular martketplace, so leveraging the users to take off some of the load.
Seems like a win-win-win. Maybe should do this with all offerings, so that stuff that people aren’t happy with never even get to the review stage, even if they seem to just glide through the review process now. Some of you have a good idea of who I mean.