Add 3 cups of epsom salt and ¾ cup of baking soda to a mason jar or large bowl.
Mix thoroughly by shaking the jar (with lid tightly sealed) or stirring with a spoon.
Add 30–40 drops of essential oils: 20 drops lavender, 15 lemon, and 5–10 tea tree.
Shake or stir vigorously until the oils are evenly distributed with no clumps.
Store in an airtight container. Use 2–3 tablespoons per load during the rinse cycle.