Section 87U. All students enrolled in registered schools shall, within fifteen days after entering upon their courses of study, be registered with the board by such schools. Students at registered schools may, within such fifteen day period, register with the board. No fee shall be required for such registration. No student shall practice hairdressing, manicuring or aesthetics upon any paying customer, and no school shall directly or indirectly make any charge for services in connection with such practice of hairdressing, manicuring or aesthetics. A school shall not pay a student for any services rendered by him.