Yep, you're over thinking this.
Wash out the cooler with bleach water.
Hang the PFD out so it stays dry. A good reliable PFD is supposed to smell like gym socks anyway, but by spring you should be just dandy.
The rest of the stuff that is non fabric, wash with bleach.
Bleach may eat your fabrics, like straps and stuff, so go easy with it there and rinse well with water, then hang out to dry.
And next time, check that stuff sooner after your last trip.