There's a reason Choice band Crobat didn't receive an OU analysis last gen. First of all its attack is pretty pathetic for a banded pokemon. The only reason talonflame can use band is because its high power stab moves (brave bird and flare blitz) synergize very well together and allow it to get through pretty much anything not rock type or heatran. Talonflame also has gale wings, which allows it to outspeed scarf users faster than it.
Crobat on the other hand, has cross poison as its other stab move. This doesn't synergize at all with brave bird, and ensures that neary any steel or rock pokemon can wall it. In addition, cross poison has low bp, and an electric type such as thundurus i can easily check it. Inflitrator doesn't make it viable by any means. As someone already said, there are pokemon who can take advantage of that ability much better. Your better off phazing than trying to put something to sleep with a 60% accurate move. Its only niche in OU really lies in having defog and a very fast taunt.
Crobat on the other hand, has cross poison as its other stab move. This doesn't synergize at all with brave bird, and ensures that neary any steel or rock pokemon can wall it. In addition, cross poison has low bp, and an electric type such as thundurus i can easily check it. Inflitrator doesn't make it viable by any means. As someone already said, there are pokemon who can take advantage of that ability much better. Your better off phazing than trying to put something to sleep with a 60% accurate move. Its only niche in OU really lies in having defog and a very fast taunt.