I have done this and found that as long as I used a bare bottom tank to make clean up easier they were worth it. They can foul a tank really quickly if not cleaned out of the tank after about an hour of feeding.
You also have to start a new batch about every 3 days or they start to stink.
Hope that helps.
I use it for fry, and supplemental food for some of my smaller fish. It is easy to maintain cultures, but if your not in regular need(regular breeding), than it is hard to justify keeping it.
It smells all the time Carol =P