That's what I'm experimenting with now, at sfrose's suggestion.

It takes LOTS of money to do lots of experiments with it! YIKES!

So far after about 100 tests, I'm finding certain patterns for how it changes fish, but nothing 'predictable' enough to write about yet.
What is does, is change either the body type ... or the fin type, of "one or some" of the fish in a tank. Or....... as you've found out .... "NOTHING"! About half of my tries to nothing... at least nothing instantly visible.
The 'geneticly altered' fish show up as being first generation of the type they alter to, so you can't see what they started out as. Gets pretty confusing.

So far, I'd say that if you have a tank of fish you don't need ... and are looking for magic fish, or the perfect fish, dropping some of the chemical in might just give you something you need!

Or, as you said, do nothing.

Fatfish sometimes turn into Snooopers.. but keep an eye on the fins when you use it. Some fin changes can be pretty hard to notice. I've never had both the fin and body change .. so I log what I put the chemical on, and then figure out which changed to what.

If I come up with definate rules for the chemical, I'll post them here... and maybe I'll start a blog about what they 'sometimes' do, on my website. (I really need to get a life!)