Honing oil

Honing oil is a liquid solution that aids in sharpening different machinery. One of the most common type of honing oil is the one used with sharpening stones. Not only they protect the sharpening stone but they also keep the stone pores from clogging.
There are different types of honing oil and substitutes. It has been noticed that some people use water instead of honing oil to make the sharpening process smooth. Although, water is no substitute of honing oil according to many chefs and experts.
The thickness of honing oil matters a lot. For example, motor oil, which is another type of honing oil, cannot be used with sharpening stones since it is too thick and instead of protecting the sharpening stone pores, it will clog them. 
Composition and toxicity.
The composition of honing oil is simple. There are two types of honing oil. One is the water based honing oil and the other is petroleum based. Chlorine and sulfur are the most common chemicals that are found in petroleum and mineral based honing oil.
Some honing oil could be toxic for specific materials such as petroleum based honing oil for sharpening stones. Windex, Simple Green and Lansky are some of the most common honing oil manufacturers.