Put at least 3 tbsp dried herbs in the quart jar, fill with apple cider vinegar, and shake well.
Let steep for 2-4 weeks.
Strain out and discard the herbs, then pour the infused vinegar into a glass bottle.
To use, mix 1/4 cup infused vinegar with 1 pint of water in a shower-safe squeeze bottle.
Notes
After shampooing, squeeze it onto the roots, massage it into the scalp, comb through with a wide-tooth comb, and rinse well, then condition. Use it once a week. If your hair feels oily, use less vinegar; if it feels dry, use up to 1/2 cup. The infused vinegar keeps well in a closed glass bottle, but mix the diluted rinse fresh each time since it contains water. Safety: keep it out of your eyes.