I prefer a piece of a branch for a tree, It gets red and lasts for long time, when bamboo stick burns too quickly, and the red area is too small.
The sieze should be 1/2 of the nail of your small finger... So bigger then you would think. It is easier to put the medicine on.
Make your medicine as watery as possible, this increase the absorption. Put the water on the bamboo stick for a some time without scraping, and then scrape it, it will come off easy, and then put some more water, mix it and then apply it...
Water, I don't know anything of saliva
Jox