The new wet sides have a light dab of silicone grease on them. Per a conversation with Ecotech it's a specific one that isn't readily available in small quantities, but anything reef safe should do (and an emphasis that it shouldn't be needed beyond new equipment startup).
I would also check the condition of the wet side magnet.
If you do decide to try your luck with the bearings I've done dry side bearings in several older MP40s and MP60s, although I haven't had occasion to do an MP10 yet. I'm happy to help assist if you're willing to bring a decent battery terminal puller, which makes the bearing removal tons easier.
This isn't the cheapest I've seen, but they look like this:
https://www.amazon.com/Z-Red-BK706-Battery-Terminal/dp/B007QV4JW6
DO NOT buy cheap bearings.
If you can't borrow the tool then with that and bearings you're going to be somewhere in the $50 range. Up to you if that's worth the risk and effort, I think a new dry side is a bit north of $100. If you do order a new dry side and assuming this is an older (white controller) MP10, call Ecotech and ask about compatibility. According to the QD upgrade chart the controller is the only change from the ES to QD models, but is at least one MP10 configuration out there that's not compatible with the controller (guess how I know this).
While it's only buying you time, if the bearings are just barely making noise and it's an older MP10, you can swap out the controller with the QD controller which will quiet it down a bit. Fortunately the controller is back compatible.
