OK, I'm brand new, found this site because I googled Liquid Keratin and "reviews" and found this thread. I read what I thought was the whole post and decided to try it... then today discovered all the other replies with the people less than pleased. After reading though, I decided to join and give what has happened to me to help out people that are deciding. I'll update once I'm done, too
As of right now, I have done everything just as the instructions said. I washed with just the shampoo, towel dried / air dried it for a bit, then hosed my whole head down in the spray. Left it on for 30 minutes - noticed as it dried it was not at all frizzy. Blow dried with a round brush and it felt pretty heavy (like I had in a lot of product... which I do) then straightened it with my Chi. It's really stright, but I'll be honest my hair usually straightens pretty well. It took about the same amount of time it normally does. My only "complaint" would be that it looked / felt greasy. I did seriously hose it down though.
I am waiting until tomorrow night (48 hours) to wash it. It smells ok, nothing great, and it just doesn't feel all that clean to me but I don't use much it in usually to straighten. I'd rate myself as a 2b/3a (depends on the day, place on my head... ) and I have a TON of hair. It's also pretty long, goes about to my bra strap in the back. Gets a little dry sometimes but pretty manageable. I would not, so far, recommend this to anyone with fine hair personally... oh and mine is highlighted. No issues with the color, it was done around a month ago.
OK, that's it. I'll let you know what happens when I rinse it out