Autozone wheel bearings went in it each time and after about 5-6k miles it would be bad... solution was to get an entire hub from the junkyard for $20 and call it good. It rolled another 40k like that until she sold it.
I have had the same problem... But it was not a grease problem (most newer wheel bearings are a sealed bearing, so no way for you to grease them). The problem is the Autozone cheap bearings are made in China and just crap.
Try and find a place that carries Timken or Chicago Rawhide bearings. Those are two that I have had luck with in the past. That said, I think both USED to be made in the US, but it has been a few years (over 5) since I had to do that research so it could have changed by now.
It turns out, the bearings are usually double ball bearing which totally sucks imo.. I'm going to try to find a way to see if I can get some tapered roller bearings for my civic in place of these ball bearings.. Totally disgraceful that they'd use ball bearings.