I stepped in some oil/asphalt mixture in a parking lot on the way to the airport. I went to the bathroom and used a paper towel to try and remove it from my shoe. My paper towel was only smearing it and actually making it worse. Remembering that lemon essential oil breaks down petrochemical products, I took off my shoe and placed a few drops of lemon oil on the sole. Within minutes the tar started to break down enough to be removed with my paper towel. The bathroom also smelled great!