The best floor stripper for heavy finishes is often considered to be the Zep Heavy-Duty Floor Stripper. This product is highly effective due to its powerful formula that can dissolve multiple layers of tough floor finishes and sealers. It is designed for use on a variety of surfaces, including vinyl, tile, and concrete, making it versatile for different flooring types. 
Zep Heavy-Duty Floor Stripper works quickly, reducing the time and effort needed to remove stubborn finishes. It is a low-foaming solution, which makes it easier to rinse off and leaves less residue, ensuring a clean surface ready for refinishing. The product is also concentrated, allowing for dilution according to the level of finish build-up, which can be cost-effective for large areas.
When using Zep Heavy-Duty Floor Stripper, it is important to follow safety precautions, such as wearing gloves and ensuring proper ventilation, as the chemicals can be harsh. Additionally, it is advisable to test the stripper on a small, inconspicuous area first to ensure compatibility with the flooring material.
Overall, Zep Heavy-Duty Floor Stripper is a reliable choice for professionals and DIY enthusiasts looking to tackle heavy finishes efficiently.