I think if the audience was made to think that the blenders worked, but they didn't it would have been better. And then it's like "wow, why would you want to kill a fish?" if they pushed it.
I guess I think that kinda thing is just fucked up and anti-productive. Kinda like the way using the word nigger is not avant-gard it's just a low brow regression. see, this would have been much better if they were commonly used food animals. and then you had to drink or eat the results.
people just don't care about fish enough.
Or make a game of it, russian roulette style.
There are fish in five blenders and the artist holds his hand in the sixth. The audience is invited to flip a switch that randomly turns on one of the blenders.