Short answer: it depends on your betta's personality. Try it, see if it works, have a backup plan in case Blueberry decides he doesn't like company. That's what I had to do with Freedy.
Dwarf frogs most enjoy bloodworms and HBH frog and tadpole bites. I would hesitate to feed them fish food because of possible intestinal blockage and nutritional differences. They do tolerate the same temperatures as bettas, so that isn't an issue.
If you have any other questions, just ask. :)
Robert Falcon Scott - Red salamander HM plakat
Passed on- Friedrich "Freedy"
Four African Dwarf Frogs - Dorkus, Sporkus, Baron(ess), and Bubbles!