For me, the main reason is that I now have to wash my hair with anything about 1/3 as often. Saves a lot of time!
I don't even use baking soda. Here is my routine:
Whenever hair looks a little dreary, brush under warm running water with a ventilated brush (the kind that has widely spaced bristles and slots that let the water run thru between rows of bristles). This distributes the oils.
When hair/scalp starts to feel oily or itchy, or when dandruff appears, put into a container (empty yogurt bucket or similar) 3/4 cup apple cider vinegar, 5 drops tea tree essential oil, and optional 3 drops other essential oil that smells pretty. Take into shower. Rinse-brush hair as above. When it is thoroughly saturated, fill bucket to near the top w/warm water. Hold hair away from scalp w/fingers, pour some of the mixture onto scalp, and rub w/fingertips. Repeat on the next section and continue until whole head is done. Dip ends of hair into remaining mixture and rub it in. Leave in for a few minutes while washing rest of body. Rinse-brush. Hair will feel oily and smell vinegary now, but it will be much better when it dries.
At first, I alternated this method of washing w/shampooing. That is, instead of shampooing every 3rd day, I would shampoo on Day 1, vinegar rinse on Day 4, shampoo on Day 7, etc. After a few weeks I found that my hair was not feeling dirty on washing day, so I began delaying until it seemed to really need it and just using a quick rinse-brushing to tame funny-looking hair. After 4 months my hair didn't tolerate the shampoo anymore--it was frizzy and weird for 2-3 days after shampoo--so I did just vinegar. Now I do a vinegar rinse every 8-10 days and a plain rinse-brushing every 3-4 days.

I have thick, wavy hair a little past shoulder-length. It used to "need" a heavy conditioner to hold down the frizz and keep the waves together. No more! This method gets the dirt and a lot of oil out (I actually have to be careful not to slip in the oil that runs out of my hair onto the shower floor!) but leaves enough oil on the hair shaft (as opposed to the scalp) to give me lovely waves. When I get out of the shower, I just comb my hair, put in barrettes or whatever, and let it air-dry, then brush it out when it's dry, and it looks great! Glossy, fluffy but not frizzy (except in bad weather), nice curls at the ends and subtle waves higher up. It also smells fresh and clean, even if I have to be in a place that's smoky or otherwise bad-smelling; I think the vinegar neutralizes odors.
Your mileage may vary. But I think it's worth a try.