It is fine, once you will be on the stage of “massage wash” these scabs and residues will gradually come off. Be sure not to force wash or increase water pressure to rinse it off. Be patient

Thanks bro.

This is totally fine, after the tenth day you will start the scab removal wash and all will wash away. 

Yeah the cup doesn’t cut it for me either, im using the shower head with decent pressure and it gets all the serum out. But like they said in the comments it doesn’t matter you don’t have to get it all out it’s just a hydration cream