Wella Kolestral is an outstanding deep conditioner for dry, brittle hair. Before I came to the hair boards, using Wella Kolestral to treat my dry hair was the only thing I was doing right for my hair. I have used it consistently for several years. After just one treatment, you can actually see a noticeable improvement. I have used it under a heating cap for 30 minutes and also without heat for 30 minutes or less. Often, I will use a small amount as a leave-in. I highly recommend the Kolestral. It works wonders for my relaxed 4a hair.
HTH