Objective: To clean my hair.

Which of the following solutions is more sound in terms of naive physics reasoning?

Options:
-- Use some shampoo and conditioner in the shower. Work it in with hands and rinse with water after.;
-- Use some shampoo and conditioner in the bedroom. Work it in with hands and rinse with water after.;
Use some shampoo and conditioner in the shower. Work it in with hands and rinse with water after.