Could you clarify what you mean by "Compost Clean"?
There are a few possibilities:
A compost cleaning product or brand – If "Compost Clean" is the name of a product, company, or service, let me know the country or where you saw it.
Clean compost – This refers to high-quality compost that is free from contaminants such as plastics, glass, chemicals, weed seeds, and harmful pathogens. Good compost is dark brown, crumbly, smells earthy, and is rich in nutrients that improve soil health. (Wikipedia)
Compost cleaning or compost management – This can refer to keeping a compost system clean by maintaining the right balance of "greens" (nitrogen-rich materials) and "browns" (carbon-rich materials), turning the pile regularly, and avoiding items like meat, dairy, oils, and plastics that can cause odors or contamination. (Southern Living)
If you saw "Compost Clean" on a product label, website, advertisement, or social media post, send me a photo or link and I'll explain exactly what it is.