is there a footnote to that "toothbrush"
it is commonly rendered as tooth wood, although PTS has tooth-pick.
If I remember correctly Ajahn Chah talks about using a charcoal stick although the common (version) used now (if it is different?) has one end like a tooth-pick and the other end is beaten into individual strands to be bitten.
Tanissaro in the BMC1&2 discusses it
BMC1 PC40 wrote: 40. Should any bhikkhu take into his mouth an edible that has not been given — except for water and tooth-cleaning sticks (§) — it is to be confessed.
"Now at that time a certain bhikkhu, living entirely off of what was thrown away (§), was staying in a cemetery. Not wanting to receive gifts from people, he himself took the offerings for dead ancestors — left in cemeteries, under trees, and on thresholds — and ate them. People criticized and complained and spread it about, 'How can this bhikkhu himself take our offerings for our dead ancestors and eat them? He's robust, this bhikkhu. He's strong. Perhaps he feeds on human flesh.'"
BMC2 personal grooming wrote:Care of the teeth. Toothbrushes, dental floss, toothpaste, and tooth powders were unknown in the time of the Buddha. However, there is an allowance for tooth wood, which is the same thing as the tooth-cleaning stick discussed under Pc 40. The Buddha extolled the virtues of using tooth wood as follows: "There are five advantages in chewing tooth wood: It makes the mouth attractive, the mouth does not smell foul, the taste buds are cleaned, bile and phlegm do not coat one's food, one enjoys one's food." At present, toothbrushes and dental floss would come under the allowance for tooth wood. Because tooth wood should not be less than four fingerbreadths long, many Communities extend this prohibition to include toothpicks less than four fingerbreadths as well. Toothpaste and tooth powder, because they are composed of mineral salts, would come under the allowance of salts for medicine.
"There are five advantages in chewing tooth wood: It makes the mouth attractive (§), the mouth does not smell foul, the taste buds are cleaned, bile and phlegm do not coat one's food, one enjoys one's food. I allow tooth wood." — Cv.V.31.1
"A long piece of tooth wood is not to be chewed. Whoever should chew one: an offense of wrong doing. I allow tooth wood eight fingerbreadths long at most. And novices are not to be flicked with it. Whoever should do so: an offense of wrong doing"... "An overly short piece of tooth wood is not to be chewed. Whoever should chew one: an offense of wrong doing. I allow tooth wood four fingerbreadths long at the very least." — Cv.V.31.2
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