My daughter has eczema and takes oatmeal baths. The oatmeal bath I used to buy cost about $6 and had 5 packets in it. That's $1.25 a bath. Too much for my pocketbook. So I decided to make my own.
I used the Walmart brand of oats.
All you need is to blend it for a long time so that there are no big pieces in it. You want it to be powdery.
I store the oatmeal in a mason jar. I use 1/4 cup in my daughter's bath.