I've never owned wet okole seat covers, so I can't say for sure...but I have owned a few funky smelling wetsuits in my time...

I'd find a large clean vessel (bath tub or new plastic garbage can) & give em a bath in some laundry detergent...lather, rinse, you know the drill...

Throw em over the back of a lawn chair or three until dry...mebbe spritz em with febreeze?