Honeybees do like mustard.
I have some honeycombs on a top cover atop some empty mediums right now, since this morning, honey has leaked out all over the cover. I have 7 hives near it and they're not interested in it. Amazing, isn't it.
They've got other things on their minds, like fresh nectar and pollen. I did put some on the speaker box bees and they are lapping it up, but the other bees are just ignoring it. The honey is light in color and mild. Very delicious BTW.