I found a couple sites for this product...This one is a pretty good price for it. Although $20 for 4oz is pretty steep. From what I can tell this is meant to help you jump-start your pod population in a new tank, or for starting your own culture. I think that a mandarin would go through the bottle pretty quickly if you were to simply try to feed the tank with them.
I hadn't seen this product before, and I'm actually somewhat excited that you found it. I think I'll order some and try it. I've still got the 10g tank that I had setup as an amphipod breeding tank. I need to empty it and start it over and this would be a cool product to try out that way.
Maybe setting up a small tank this way, and using half the bottle to start your own culture and half to feed to your tank directly you could keep the mandarin fed well enough that you wouldn't have to get rid of it.
B