" 'powerless' doesn't quite work, but the others are fine. It's more usual to say that the person was powerless (to change the dog's behavior) than that the method itself was powerless. CJ
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
AngliholicIs "ineffectual" in the above equal to "ineffective, useless, powerless, and futile?"'powerless' doesn't quite work, but the others are fine.