UPDATE: It's been over 6 months since I first started using henna and I will never go back to "regular" dye. I have learned to mix this better and I don't have to use a full cup for a whole-head dye job. I can get away with using about 3/4 of a cup and I make it a little thinner & leave it on longer. I have left this on for as long as overnight & get much better results with a thinner mix. The trick is that the henna only "works" as long as it stays damp on the hair so I cover or wrap it with a small damp cloth or bandana, then cover that with plastic caps or plastic wraps to keep the moisture from drying out. For my afro and semi-coarse 4B/4C hair this lasts about 7 to 8 weeks before my gray starts to peek through. With the Burgundy, my grey turns more ashy-Burgundy than the darker parts of my hair. I can use just about 5 tablespoons of the henna to do a touch-up on the edges when the grey peeks.This seems to add strength to my hair. I still get breakage if I don't take time to detangle, but my overall hair health is better than when I was using regular dye. And this is, surprisingly, much less messy than dye. By the way, I mentioned the smell of the henna. It does wash out 7 dissipate but you also need to rinse or throw away any paper or cloth towels to get rid of the smell or it will linger.I tend to do a lot more deep-conditioning when I am using henna. That seems to help the color last.ORIGINAL REVIEW:I was so worried about using henna because I'd heard warnings about the mess & the effect on 4C afro-natural hair. I should never have hesitated. This is just as easy to use as is "regular dye" & I prefer it since it's "natural". The wet-grass-dirt smell is the only thing I didn't like. It didn't linger after rinsing, thank goodness. By the way, I only used half of this for my amount of hair (see photo). So 2 uses per jar. Not bad on the wallet.I had already used the Dark Brown/Sable shade before getting this color and the results I got were amazing. Because I had already dyed my hair black with a traditional method, you can't see the results in photos. However, my hair is softer and stronger after just one henna treatment. I typically have to deal with "crunchy" hair after a wash until I put in a ton of product. The henna left my hair strawlike - which was terrifying - after I rinsed but doing 5-minute deep conditioning solved that. Once it was completely dry, I had no "crunch" or texture problems.Rinsing this out was an ordeal. I did the first warm-then-cold rinse for what seemed like 5 minutes and there was still some grit and clumps when I checked. I ended up rinsing about 4 times before everything was out. Then again, I have thick, afro-kinky hair.This did elongate my natural curl pattern but only slightly. Now, when I wash, I have less shrinkage and breakage. It really did strengthen the strands.The one thing I have not discovered yet is how often I will need to do this to keep the gray hair covered. I am guessing I might need to do another treatment once a month or every 7 weeks maybe.As far as worrying about the mess, this was less messy than dye that rips and runs. Once I got this mixed and on my hair, I had zero problems. When some got on the kitchen backsplash and in the shower during the rinsing, it was really easy to wipe up. I used some oil on a paper towel and it came right off the painted & textured backsplash. For my shower, which is a kind of hard rigid plastic, this washed out with the shower spray.For people who use grease or oil on their scalp or hair, you will want to wrap your hair if damp when going to bed. I did get some residue the first time I finger-styled my hair using an oil cream product. That actually made sense when I read that the way to get henna out of your hair quicker is to use mineral oil.The instructions are great (and can also be found on the brand's site) but did not specify how much liquid to powder to use. I contacted Rainbow Research and they said it's about 1 cup liquid to the same amount of powder. They said it should be the texture of mayo, oatmeal, or pea soup. I made my dense enough not to drip and I added olive oil for dry hair issues.I see no need to return to using my old dyeing methods. This is going to be a way for me to transition to embracing my gray hair. This shades it rather than totally covering it up & I like that.