Oil-based paint and stains don’t last forever ... These substances can leach into the soil or water supply if they end up in landfills or sewers, causing long-term damage to ecosystems.

There’s one called ACT Concrete Cleaner. It’s a powder that you shake over the stain. Then you take a push broom and work it in a bit, and make sure the stain is fully covered. Then, you walk away and ...