You should have washed off these crusts on the day after surgery, but now that they formed, you will have to wait a full 12 days before trying to wash these crusts off by leaving the shampoo on for 10 minutes at a time. Once these crusts are water logged and it is past 12 days, you can gently rub them off. Repeat twice a day until the crusts are off.
The patient on the right has 3250 grafts 6 days prior to shooting these photos. Notice, all you see is a small beard growth and he went to work within a day of the surgery. This is the way it should always be.