Data wiping approach(es)

The answer may differ slightly from what you expect, but I will answer the question about destroying storage. AWS uses the method described in NIST 800-88.

This is expected to be physically destroyed after one overwrite of data.

MEDIA DESTRUCTION

Media storage devices used to store customer data are classified by AWS as Critical and treated accordingly, as high impact, throughout their life-cycles. AWS has exacting standards on how to install, service, and eventually destroy the devices when they are no longer useful. When a storage device has reached the end of its useful life, AWS decommissions media using techniques detailed in NIST 800-88. Media that stored customer data is not removed from AWS control until it has been securely decommissioned.

https://aws.amazon.com/compliance/data-center/controls/

Third-party audit reports are available from AWS Artifact. https://aws.amazon.com/artifact/

I hope this will be helpful.