My coton (age 9) developed really bad breath - teeth cleaning ideas?

Poor little girl has developed the worst stench in her breath over the last year or so. No changes in food or activities. I've never really brushed her teeth, maybe a couple times, but she will almost never let me do it. I've tried the bones that claim they clean dog teeth as they chew but she eats the soft ones up in about 2 seconds. Does anyone else have a solution to this problem? Anyone use water additives or special toys/treats? Any and all information is appreciated- thanks!