Final answer:
Shampoo trays and bowls should be cleaned after every use with soap and water to remove residue and maintain hygiene.
Step-by-step explanation:
Shampoo trays and bowls should be cleaned after every use with soap and water.
When shampoo is used, it can leave residue on the surface of the trays and bowls. Water alone is not effective in removing this residue because shampoo contains oil-based ingredients that are not easily washed away with water alone. Soap helps to emulsify the oil in the shampoo, allowing it to be easily rinsed off.
Cleaning the trays and bowls after every use helps to maintain proper hygiene and prevent the buildup of dirt and bacteria.