Yep. Every Monday at either coffee or lunch break they get swung down beside the smoke gate and pumped out. At least that's how it's done on on the towers I've worked on. Bigger sites they'll do 2 or 3 times a week. The drywallers will still just shit in buckets and hide em in a closet.
Worked a job where they wouldn't dump them so the iron workers would set them on fire to get a new one.