Question: how to clean very dirty engineered hardwood floors?
Answer: Clear debris. Clean and clear the floor of all debris, dirt and dust using a vacuum cleaner, soft bristle broom, dust mop or microfiber mop.
Wet your mop. Lightly wet your mop pad or wipe with clean water.
Apply Simple Green Multi-Surface Floor Care. ... 
Mop up in sections. ... 
Air dry.