It is not your imagination about Jamila henna, it has the LONGEST dye release time. That is why I don't usually make it my top recommendation for use on hair because most people, including myself, like to do henna on the spur of the moment and just mix and use. SO I usually recommend Moroccan (which has the fastest dye release of all hennas), and Indian henna. I have been testing the new crop of Oct/Nov 2006, and I found the color of the indian henna to be even brighter then the moroccan and even my hubby complimented me on that. But sometimes that happens when the crop is very fresh.
Indian has a very good dye release as well, not too long and I decided to mix and let mine sit for only 1 hour and apply. I usually leave it overnight as that is really the only time I have available to do henna. Wash it out and it was nice.
This was a henna herbal blend from our supplier to test out. It was nice.
Shikakai is one of the more popular hair conditioners and for growth along with cassia and amla.
For the dry hair I would recommend that you either do a henna gloss in between, or use amla oil right after an application. Because it can get too hard and dry for some people, everyone has a different scalp and texture of hair.
Or try the ghassoul as well in between applications, many customers with dry hair tend to prefer that. It is very softening and it comes from Morocco. Morocco is in Africa as well, so it does work very well. Moroccan friends of mine who have drier hair tell me that.
For ghassoul (also known as rhassoul) is also a great facial cleanser (mud masks).