I'm certainly happy to try stuff. I'm certain I'm not the first to ever use zinc oxide in my soap, though!
Well, I made a batch using about 1 TB of zinc oxide to color half of my 1 pound mold. (1 TB per 1/2 lb oils)
I would not be able to compare to titanium dioxide as I've never used it.
(The zinc certainly needs to be stick blended if there's any hope of not having small clumps.)
So, I stick blended it into half the batter to make a two layer bar. This base soap recipe usually yields the standard handmade creamy-colored bar.
Unfortunately, I decided to experiment with vetiver eo, which changed the base color of the soap to a much deeper cream color. So, my zinc part is definitely whiter than the non-zinced part, but it's still creamy because I used vetiver. Oops.
It's only been curing a few days so I don't know how it'll feel being used.
After cure, I'll report back if anyone is interested.