I most likely imagine she's doing a form of Japanese pickling (only seen it done in a few series so don't know the name). Digging around I came across Nukazuke, though I don't know if that is exactly what she is doing. It does have a similar appearance (wiki commons image) and involves pickling vegetables in a rice bran mash that has a consistency similar to wet sand. The mash has to be stirred daily to prevent it from going putrid, and going by wikipedia it is recommend that it be done using clean bare hands.
