Infant Temperature Nipple

My exclusively-breastfed baby won't take a bottle of expressed breast milk. We've tried it all - from many different nipples and bottles, to warming the nipple, trying it when the baby isn't very hungry, different milk temperatures, a stranger feeding the baby, etc. etc. etc. Really, we've been down the list of things to try (apart from starving her, which I don't want to do) from Dr. Sears and other online sources.

We thought we might like to entice the baby by putting something sweet or tasty on the bottle nipple - just to see if she'd start sucking. However, honey, corn syrup and maple syrup are all unsafe choices due to the small risk of infant botulism. Does anyone know of anything that IS safe? My baby is not on solids yet, so nothing like applesauce would be acceptable.

Thanks so much in advance!