I think you might do better on a website focusing on home made toiletries/remedies (there must be some?) But I can tell you that cornstarch is often mixed in talcum powder, or used instead of talcum powder - e.g., on a baby's bum. So perhaps it has the same drying quality you're after.

Bob's Red Mill and King Arthur Flour both carry tapioca flour aka tapioca starch. Texturally it's slightly silkier than corn starch, and when I try rubbing a bit of each into my skin the tapioca disappears a little better. You could give it a go with cornstarch -- what's the worst that could happen?

I think they mean "tapioca starch" or possibly "tapioca or cornstarch". Cornstarch is a good absorbent for moisture. Which may be why it's used in baby powder. Of course, now, doctors and nurses don't recommend using baby powder for diaper changes.

Thank you so very much amysarah!!

Thank you all for the excellent info!!

Cornstarch will work, but it may leave more of a residue. I've tried a few diy deodorant recipes and haven't liked any (I make all of my own cleaning products and love them) so do report back if you like it.

Lol thank you...

I have this "recipe" for a deodorant that doesn't use any starch.

Mix a few drops of essential oil (like lavender) with rubbing alcohol in a spray bottle. This is merely a deodorant, not an anti-perspirant. The alcohol kills bacteria that causes odors and the lavender is also antiseptic in addition to being a fragrance. I've been using this deodorant spray for the last 3 years and it works really well. Again, it's a deodorant. It won't 'keep you dry'.