I don’t see why it wouldn’t be effective. It’s not like an unplugged solid body electric bass is silent when you play without it being plugged it. I find corded headphone practice to be cumbersome, but I still do it on occasion, and in fact, I’m preparing to do it more often, since I now live in a multi-unit stick-framed building and my bass amp literally rocks the whole house. Maybe I should try that new Boss wireless headphone deal. Somewhere around here, I even have a Dragonfly stethoscope practice device, which is also kind of cool.