Conversation so far:
What was one of Miyamoto Musashi's teachings?
Miyamoto Musashi created and refined a two-sword kenjutsu technique called niten'ichi.
What were some of Miyamoto Musashi's other teachings besides niten'ichi?
Today Miyamoto Musashi's style of swordsmanship with a jitte is known as Hyōhō Niten Ichi-ryū.
Was Miyamoto Musashi popular?
It is difficult to separate fact from fiction when discussing Miyamoto Musashi's life. There have been numerous works of fiction made about or featuring Musashi.

Question: were his teachings followed?
Self-contained rewrite: Were Miyamoto Musashi's teachings followed?