Please do not use any bleach-based cleaner on the canvas or vinyl portions of a PUP. While it does take care of the mold on the surface, the area still contains spores and is more likely to grow mold faster when moist conditions are reintroduced. When researching this for myself previously, too many sites explained why killing mold on porous surfaces does not eliminate mold. See
here for one source. A brief exposure to bleach will help shorten the overall life of the materials. Even with a lot of water, you will not be able to flush all of it off of the canvas. You would need to remove the canvas and rinse it vigorously to remove all of the bleach. Bleach is a base and is slick when contact is made. Personal experience of having bleach on my hands has shown me that it takes an incredible amount of water to remove it to the point skin no longer feels slick. It takes even more water to reduce the odor. Unless rinsing with something like a power sprayer, some residue will be left even if it is diluted. This is the portion that accelerates the slow deterioration in the long term.
Instead, use a mold cleaner specific for vinyl and canvas.
I have personally used
Iosso Mold and Mildew Stain Remover with great success. It is biodegradable, non-chlorine and is odor free. I mixed the powder per the instructions with water, applied it with a small paint brush, let it sit, rinsed it lightly and blotted dry with a towel.
I had no further recurrence of mold, especially after resuming vigilance over ensuring everything is completely dry before putting it away for good.