Schaeffer's manufactures a wide variety of concentrated industrial strength cleaners!
These products will work for many difficult situations. "Concentrated" means that you are not paying for water! Check them out.
Here are some verified reviews:
"Citrol Degreaser-Citrol Degreaser is by far the best cleaner that we have used in 40+ years of business in the asphalt industry! We highly recommend it!!!" Michele B.
"Citrol-This is an amazing product I'm so glad I have it at my shop!" James S.
"Schaeffer 266 Citrol Citrus Degreaser Cleaner-This is great stuff! I do die cut vinyl decals and Citrol is the best at taking adhesive off surfaces. I recently bought a used van that the previous owner had sprayed rubber liner over the entire exterior surface of the van. Citrol was able to break it down and allow me to remove it with relative ease." Kurt S.