There are several natural or eco-friendly alternatives to chemical paint strippers. One alternative is using a mixture of baking soda and water, which can be applied to the paint and left for a few hours before being scraped off. Another is using a mixture of vinegar and water, which can also be applied and scraped off after a few hours. Sandblasting with walnut shells or corn cobs is another option, but it may not be suitable for all surfaces. It is important to note that these methods may not be as effective as chemical paint strippers and may require more time and effort.