YouTuber NileRed tried this a couple of times, and had pretty decent success his second time around: https://www.youtube.com/watch?v=uUU3jW7Y9Ak
https://www.youtube.com/playlist?list=PLD4KfY4Nafgv6enUyv9Mw...
You have a point about "s" and "th" which is a whistling between tongue and palate.
There are also plugins that take care of at least most of it now, but it's not going to get rid of every instance of it. In current year, if you want 100% of it, it makes more sense to just train a model on your speech and fake all of the audio instead of recording it, then re-record only the parts you don't find acceptable.
On the opposite side "chemical force" is amazing and borderline unwatchable.
Also StyroPyro for an electrical mad scientist version.
…now that I go look at his channel apparently Thoisoi's lab just burned down.
Thanks, subbed to him!