Tiffany, aka Struttswife, recommends the following
Live Curly Live Free - Home Remedies
Apple Cider Vinegar Rinse
There is some debate on whether or not an apple cider vinegar (ACV) rinse alone can clarify the hair; however, it is helpful to bring the hair back into balance after an alkaline solution has come into contact with the hair and will shut the cuticle back down. Repeated use of ACV rinses can be drying, so limit use to once or twice per month at most:

Combine:
1 tablespoon apple cider vinegar
1 cup warm water

Pour the mixture over the hair after cleansing (do not rinse out), then condition as usual. Any lingering smell will dissipate as the hair dries.