Go to a local pottery barn and melt the hard drives into liquid in their kiln and you can be sure.

WIPE Drive from white canyon is NSA approved.

Certified by NIAP to EAL 4, higher than any other software wiping tool.

https://www.whitecanyon.com/wipedrive-enterprise

Compatibility

• All computers with an x86 architecture
• All versions of Microsoft® Windows® (Windows 8 and 10 with disabled boot security)
• Intel-based Mac computers (starting with OS X v10.6 "Snow Leopard") that can boot from a CD
• Linux machines that can boot from a CD

WipeDrive meets or exceeds all major national and international regulatory and technical standards including:

• Sarbanes-Oxley
• HIPAA
• Common Criteria Evaluation
• FACTA standards
• NIAP's EAL4+ security standard
• U.S. Department of Defense 5220.22-M
• CSEC ITSG-06

Uses industry standard approved methods for data wipe such as Secure Erase for SATA and Sanitize for eMMC. See NIST Special Publication 800-88 Guidelines for Media Sanitization for more details.

https://www.dell.com/support/article/uk/en/ukdhs1/sln312291/dell-data-wipe?lang=en

https://csrc.nist.gov/publications/detail/sp/800-88/rev-1/final

That wasn't acceptable to Company Grade officers and Higher.  They want the drives shredded by turtle wings.

https://datakillers.com/our_services/destruction-services/data-destruction/

The current shredder reduces them to 2MM dust.

https://www.youtube.com/watch?v=uQ6ffBE0s50

shredding