Worked great!
I've generally gone to a salon to get Keratin treatments 2x a year, but I have since moved to another state and I haven't found anyone yet or it costs a lot more than what I used to pay.  I purchased this about 6 months ago, but finally got around to using it this week.  I washed my hair first with the clarifying shampoo and let it dry, then I painted a small amount all over my hair (I used less than suggested and I have shoulder length hair).  I did it alone and it still wasn't difficult.  Probably took me 2 or 3 hours start to finish.  I followed the directions and dried my hair afterwards, then flat ironed.  I let it stay in 48 hours, so I can't say if there would have been any difference if I washed the next morning.  It worked great, and my coworkers remarked how shiny my hair looks.  You need to do in a well ventilated area and make sure you have gloves, an applicator brush to put on and a comb to work through hair.  I gave it 4 stars as I can't speak to how long the results will last but I am very happy with it so far.
Rating: 4 stars