Keep in mind that whatever you feed your roaches goes into your frog. The better you feed your roaches the better you feed your frog! I would not feed them coffee as I would not want to feed my frog coffee. Pretty much any table scrap fruit or vegetable would be good for them to eat. You could also use water crystals as a water source. A good high protein dry dog food would also be a good choice. My dubias love oranges as well and it's said that something in the oranges makes them breed like crazy.