Since everyone's hair is unique you must use your own judgment.
Remember--dry hair likes less vinegar and oily hair likes more.
For most people a using a vinegar rinse every day will be quite drying. It is best to restrict use to 1 to 2 times per week.
The amount of water you add to the vinegar, the dilution rate, will also affect how often it can be used as well as whether it is drying to your hair. You will need to experiment to find a dilution that works best for your hair type. Always start with a very dilute rinse in order to find the proper ratio for your hair.
If you like a bit of vinegar with each washing, a spritz with a very dilute rinse may work.
Some Helpful Hints
- While you can use any container to make your vinegar rinse, I like a plastic squirt top bottle. It is easier to squirt it all over my scalp and then massage it through, rather than pouring it all over my head from a cup. Recycle any clean plastic bottle with a squirt top.
- Pouring a cold rinse on your hair may be a more invigorating experience than you would like. (Although if you're feeling brave, the cold water will give your hair added shine.) If you would like a warmer rinse, make it just before you step in the shower using very warm tap water.