Teach Soap

Because of their antibacterial properties, alum crystals are popular for underarm deodorant and have been used in this way for eons. Can anyone say whether these crystals can be ground into a powder and used in a batch of soap for deodorant soap? If so, how much should be used. If not, what ingredients can be used to make a good deodorant bar of soap? I understand Rosemary and Lavender essential oils are good for this purpose, but I'm especially interested to find out if the crystals are a good idea.

No, they cannot. Soap is a wash off product; deodorant is not.

I would use an Essential Oils blend at the proper %, so the oils
will not irritate the skin.

_________________
Irena
Closed minds are like faulty parachutes; they refuse to open.

I know you were talking about deodorant soap but thought you may like this...
Anne-Marie made some actual underarm deodorant to try a while back. You can see them here;

http://soap-queen.blogspot.com/2007/10/ ... orant.html
http://soap-queen.blogspot.com/2007/10/ ... f-use.html

It was fun and we thought it was a good idea... but turned out that it didn't really cut it. The store bought deodorants just worked better. This was just one try with one recipe though, there may be better ones out there!