You can clean a fishing backpack by first emptying the pockets of all items and large dirt particles. Use a damp sponge (without detergent) to clear the outer surface of dust and dirt. Scrub any light stains you see on the surface using the sponge. If the stains are large, use a soap or detergent (bleach-free) to soften them before scrubbing. Rinse the backpack and dry it indoors since exposure to ultraviolet rays can damage it. Check out our buying guide to learn how to care for your fishing backpack.