How do I help my hoarder mother clean?

I'm only a teenager and I've tried being nice, mean, and I've even recommended a counselor. She doesn't want treatment and she can't throw things away. She buys tons of things because they're on sale or she has coupons. How do I help her clean? I've tried sitting down with and helping her clean but nothing stays clean. The house only gets worse. I don't think she truly has a clue how depressed I am due to the house. How can I help her?