I want to try using henna to dye my hair. I have naturally medium brown hair with a lot of gray. Any reddish/brown color would be good. I tried the Lush Henna a couple of years ago but I had a hard time getting to it stick but I also had been dyeing my hair with commercial box stuff for a long time. I cut off all of the henna and haven't dyed my hair in a year.

Should I try Lush again? A henna powder? Run far far away from henna?