Like every other thread asking for a tag, usual reply is, there's simply not that much of the said content for it to get a tag.
Hypnosis/Saimin works are not that many in the current subscription releases.
The only thing that comes to mind is:
https://www.fakku.net/hentai/on-off-english
So, like usual. If you think a specific fetish needs its own tag, please make a list of all the works that has the specific tag.
This will also help with the tagging process if Fakku decides to make a new tag.
Also Keep in mind.
Fakku just translates and publishes, the lack of certain tag/fetishes is out of Fakku's control.