I wrote down the ingredients and directions from the herbal bath my doula brought me after dd's birth because it was so heavenly. It's distributed by a local company and I don't think they have a website, but perhaps the list of ingredients will be useful to you:
Comfrey Herbal Sitz Bath
Organic comfrey leaf, organic comfrey root, organic uva ursi leaf, shepherd's purse, coarse sea salt
For post-partum use, heals perineum, reduces inflammation, dries umbilicus. Can be used in a bath, sitz bath, or a peri bottle.
Directions:
1. Bring 1 gal of water to a boil. Add entire contents of 1 bag. Stir.
2. Reduce heat and bring mixture to a low simmer. Simmer covered but slightly vented for 1 hour, stirring occasionally. (Optional: in the last 5 minutes of simmering, add 1 clove of chopped garlic to the mixture.)
3. Remove mixture from heat and allow to steep for 20 additional minutes.
4. Strain mixture into another clean, large container to remove the loose herbs. Cheesecloth in double thickness draped over a colander works well for this purpose. (Optional: Bring up the corners of the cheesecloth containing the used herbs and tie with string to make a sort of tea bag. Store in an airtight container in the fridge. On the 4th day all 3 of the used herbs can be added, still wrapped in cheesecloth, to boiling water to make a 4th sitz bath. Again, simmer for 1 hour and steep for 20 minutes.)
5. Use cooled mixture to fill 1 or 2 peri-bottles either with the full strength mixture or diluted up to a 50% solution with water. Store peri bottles covered in the fridge until ready to use.
6. Add remaining mixture to 6 or 8 inches of warm bath water at a comfortable temperature in a clean bath tub, or full strength in a sitz bath.
7. The mother should then sit in the bath water, soaking for at least 20 minutes.