I was reading an article about people who have stopped washing with soap
https://www.theguardian.com/lifeandstyle/2019/aug/05/i-dont-smell-meet-the-people-who-have-stopped-washing
which started to discuss Ammonia oxidising bacteria and the role it plays in maintaining a healthy skin biome. The company, AOBiome that owns the main cosemetic brand of AOB products has been moving into other produsts and trialed a nasal spray for blood pressure with great success and noted that the volunteers all said they had experienced no headaches on the trial and so the company are now trialling a spray looking at migraine occurence
https://www.prnewswire.com/news-releases/aobiome-therapeutics-expands-clinical-stage-pipeline-initiates-phase-2-clinical-trial-for-episodic-migraine-300633926.html
Thought this is an interesting line to take, modern living causing symptoms etc.