I've had luck with Joe's Juice and Peppermint shirimp - I guess I just got lucky :)

I kicked the big apistasia that was easily visible with the juice, and my shrimpies got the rest, haven't seen it come back in any of my tanks since. The nano has been free, save for one that was hiding, since I first got it...

Guess it's just that kind of stuff, works for some and not for others <Shrugs>