The variation of the band pull-apart method has you doing regular reps, but slower than usual. This is more for muscle-building than improving weak spots or improving the role of the back in the bench press.
Depending on your objective, you can vary the approach. It's practically impossible to overdo pull-aparts, so use them often.
Matt Phelps is hugely pissed about the term "failure" and what it really means. He thinks exercise physiologists have one idea while the guys in the trenches, i.e., the guys in the gym, have a different, more realistic idea.