Clearing Blocked Milk Ducts
1. Run a sink full of hot water. Bend over and put your breasts in the sink, massaging down from the back of the breast.
2. Put comfrey leaves in your hot compress (fresh or dry) to help encourage the milk flow and unblock tubes.
3. Soak breast in slippery marshmallow root. Steep the marshmallow root overnight in a half a gallon on boiling water. Reheat the infusion, pour into a sink and soak breasts until the infusion cools.
She also recommends continuing to nurse, cautiously because it can be quite sore and inflamed, to ensure milk supply maintains (once every hour) and getting adequate rest. As you regenerate with a good nights rest, it’s quite possible that milk duct will become unblocked overnight.
Source: Weed, Susun. Wise Women Herbal for the Childbearing Year, page 86-88