How To Make A Toothbrush In The Field - To make a twig toothbrush, simply cut a green twig about the diameter of a pencil and just as long. Pound the end of the twig with a clean, smooth rock. Then chew this end for a minute to moisten and soften the bristles; and finally, brush away. Survival Tools, Camping, Emergency Preparation, Homestead Survival, Brushing Teeth, Hacks, Pencil, Prepping, Diameter