I was reading an audio book of L.A. Banks Ancestors and the character said he made a toothpaste out of baking soda and linseed oil. At least it sounded like he said linseed oil. so I went on line to find information about linseed oil. What I found astonished me. Linseed oil is used to stain furniture. Imagine what it would do to my teeth. Linseed oil has a prperty that when it dries combines with oxygen to create heat leading to fire. http://abcnews.go.com/GMA/ConsumerNews/summer-safety-diy-dangers-linseed-oil/story?id=11328546 I'm not saying don't believe what you read in novels. I a m saying remember they are novels and though they may contain things that seem to be educational it's always a good idea to research stuff for yourself to get both scientific and experiential knowledge.+This is especially important for things you would put on or in your body.