Milky oats refers to the oat seed/grain at a certain stage of their growth. When they are starting to plump up and ripen they go through a ‘milky’ stage. The milk oozes out of them when they are squeezed. This milky slightly sweet liquid is very rich in minerals, vitamins and some of the medicinal components.
And yes! You can purchase them from many places that sell bulk herbal teas.