A brand audit is a clean-up with a clipboard: volunteers sort what they find by brand and product type and submit the counts. Break Free From Plastic has published global results since 2018 (Coca-Cola has topped the list for six years) and a 2025 supermarket audit report. Schools and community groups are the main contributors.
Honest caveat: the most recent global report on the site is 2023, so check the audit site for the current cycle and deadline.
How to start: brandaudit.breakfreefromplastic.org/ (toolkit and data form).