Please choose the correct solution to the question: How to clean a child's school backpack?

Solution1: After removing the contents use a mix of water and detergent to scrub all surfaces, rinse with cold water and let it dry in the sun

Solution2: Before removing the contents use a mix of water and detergent to scrub all surfaces, rinse with boiling water and let it dry in the sun

Answer format: solution1/solution2