I'd keep the wheels.
Buy a tub of either synthetic or boat trailer bearing grease, if you ride "wet".
REPACK the hubs NOW. Clean out all the old "lube" to avoid any "possible" incompatibility issues with the new grease.
MANY factory hubs come with a minimal amount of grease and poor preload adjustment. Usually too tight.
Some appear to be a thin wax type lube that was sprayed on. Usually on the cheapest bikes.