Rest and constant nursing.
Heat and cold to loosen the blockage
Massage the clogged duct.
Lots of water.
Raw garlic is good for infections.
Cabbage leaves, cold or frozen on the affected breast.
Vit C against infections.
Probiotics to help keep your immune system strong (always good).
And some say fermented cod liver oil 2x a day during infection.

I don’t know about a remedy, but cold cabbage leaves are extremely soothing on sore boobs

Warm packs on breasts before feeds, gentle massage, then cool packs on breasts after feeds.