'Influencers' are the biggest bubble of the internet. I have no doubt the biggies do a good turn, but most of these 'influencers' just whack their hottest pictures on dating websites and link up. In addition, half of their 'audience' will be bots that they've paid for anyhow.
Depending on the product, you'd probably be better paying someone to review it on Youtube.
Go back a couple of years, aye, yeah, but folks cotton on quick. You'd be better throwing it into Facebook Advertising in my opinion - at least you have a degree of control and can actually use their analytics.
Throwing a oner to someone in the hope that a few snaps will help flog your product is snake oil by drip.