Yes, you are right. I used one of those dove shampoos that needs to be rinsed off. The shampoo became dry after about 5 minutes of application like you said.
I was not given any printed instructions. I was told by the doctor to leave the shampoo for 30 minutes.
I have been asked to repeat the same steps tomorrow for 20 minutes. So I'll check with the clinic to make sure that I got the hair wash procedure right, before I do the second wash.
Thanks for replying. It has definitely helped in calming my nerves.