Old Time Capsule not working, how can I destroy data?

I have 2T Time Capsule purchased in 2013, 4th generation model, protocol 802.11N

A couple of years ago I purchased an Airport Extreme and set this Time Capsule aside as though the router was working fine, but the Time Capsule was no longer accessible. I was told that I would have to physically destroy the hard drive. To be honest, I wasn't sure how.

I need to now destroy the hard drive, which led me to investigate further. I found this article: Verify, repair, or erase an AirPort Time Capsule drive - Apple Support

When I connected the Airport Time Capsule to my iMac Airport Utility via an ethernet connection (not using wifi) it shows these two messages:

My question:

I understand that when unplugged (2 years), and then plugged in, Airport Time Capsule will self-diagnose and repair itself and that other than that there is nothing I can do to repair the disk. Is this true? I was thinking I could try Disk Utility? My concern was eliminating any "bad blocks" or ? ... I mean it says it is failing and is in need of repair, I wondered if erasing (35 erase choice) would be good enough? Or, if there is something else I need do or consider? Do I still need to destroy the hard drive even after erasing, and if so how, or is that overkill?