Just remember, that the /reflux switch command is case-sensitive. niconaze is not the same as Niconaze. Also, make sure you didn't type the " marks when you typed the command.

/reflux switch Niconaze

And CLCRet does throw a "this addon does not work on x class" message if you're not a paladin. Why the author didn't just write it so that it doesn't load for non-paladins, I'll never understand.