Fast forward to November 2024, last night I installed a 16TB Seagate NAS 3.5" hard drive in my TimeCapsule and its working great!!

Just plugged the original 3TB drive into a powered HDD dock and connected it to the USB port on the Time Capsule so I can transfer stuff to the new drive or just use the old drive as a portable drive. Lol

In my opinion, a less abrasive metal polish would probably be better to start with.