I read a fascinating (and scary) article today about baking soda for diaper rash. (https://www.ncbi.nlm.nih.gov/pubmed/7232046) Liberal amounts of baking soda for diaper rash caused a baby to become dangerously over alkalized.
I have actually never used baking soda for diaper rash, but I can see why using a significant amount on the bum of a baby and then the baking soda being wet from the diaper...yes, a lot of baking soda would be absorbed into a little person.
So, I wouldn't recommend using baking soda for diaper rash. (Besides, I think it would burn a diaper rash.)
But, I have used baking soda baths often for a variety of health issues and have figured the baking soda had to absorb into the body and help to alkalize it, which improves so many issues.
I use 1 cup per bath of 20-30 minutes once or twice a day.
I would not go adding several cups and soaking all day - you may have trouble then.
Anyway, disturbing as the article is, it does confirm to me that baking soda baths will help to alkalize the body. I will keep on using it for poison ivy, colds, coughs, the flu, chicken pox, tick bites....
~Mama to Many~