Go back to the store for frozen blood worms. They may or may not take the BS. If they do, fine, but they still prefer the blood worms and will do better on them. Their mouths are structured in such a manner they have a hard time eating anything they can't literally suck up whole.

Also, unless they are living alone, feed them at night after you turn off the tank light, when they won't have to compete for food.

I will go buy that tomorrow morning.
Are they more "bottom feeders"?

It's a tank I set up to grow water plants in
and just happened to see them at the pet shop.
I just wanted something unique in there.
They had leaf fish, but they were little to pricey for me.
I only have a few fish in there - 2 small feeder comets when I set it up.
Brought my betta in from the back yard pond
and 2 small blue botias...............cheryl

Yes, strictly bottom feeders. They use their long snouts to grub around, feeling for food and in the wild, eat tiny soft bodied crustations, insect larve, etc. They will literally vaccum the bottom, moving forward then backward as they smell food and try to zero in on it. They are certainly interesting and quite incapable of harming your other fish- unlike leaf fish, that lie in wait, then glup down whatever will fit in their surprisingly large mouths.

It won't get too warm for the comets? Bettas like warm water, being from southeast Asia and I assume elephant noses need warmth too.