So I believe I have found the best and easiest way to wash my dreads and all you need is a baby bottle..I got mine for a Buck only they are nice to have measuring on Them and a lid I did poke a few more holes in the nipple of the bottle.I have been using Dr bronners peppermint so I will put enough shampoo as if I'd put it in my hand.I will add some tea tree oil and whatever else e oils you would like fill it up with the hottest water you can stand I shake it up and I will flip my dreads up and I'll spray my dreads I finish the bottom and then spray the rest of the bottle on the top of my dreads. I will put the dreads between my fingers like root rubbing and do that with my whole head I squeeze my dreads let them soak for a few min and then I rinse rinse rinse..the baby bottle is the best way I found to wash my dreads and not use a stupid plastic tub and deal with that hassle. I usually have enough in the bottle to wash twice.I also have small shampoo containers that I have acv and baking soda in so I don't have to keep the baking soda in the tub all the time the shampoo bottle works great it's just a 4oz bottle or so that you would use on a plane. I hope this helps others out as much as it has helped me its done wonders for making It super easy to wash my dreads.
As a scalp,only washer once a week with a full wash once or twice a month (but alas, no more dreads) old sports bottles are great for getting through thick dreads/thick hair. I also have an ACV bottle, an old venue sports bottle with a sip cap. I keep a mix of ACV and water in it. The other has dilute no SLS shampoo. It's simpler to rinse than the new Dr Bronner's forumulations.
Usually I just rub Lush Seanick shampoo on my scalp. Then every other week do 3 soaks 2 with Baking Soda, lemon, white vinegar, tea tree oil, lavender oil, and rosemary oil. The last I use white vinegar, tea tree oil, lavender oil, rosemary oil, and grapefruit seed extract. The thing about the method the op describes is that it only cleans the scalp and roots leaves out cleaning the rest of the dread where other airborne residues, pillow junk etc gather. C/S, Rev J