It really depends at that point--if you are counting on the stuff not working, then, yes, I would see you falling into the same line of thinking. If you are counting on it working, then you'd be wise to start with less delicate fish and then move to the more delicate ones as you see it working more and more.
I might test it for the next tank that I do (besides the one which has already cycled at home), but I will start with Danios and such under the assumption that the stuff doesn't work.
Then I would move toward more and more delicate fish, but definitely not Cardinals until there are some well-controlled studies published by legitimate sources. (I don't count myself as legitimate for those purposes, but I would count you, RTR, or a number of other people to be legitimate sources.)