How can I delete the partition table on a USB flash drive?

I have a 32Gb USB flash drive, and I flashed it with a bootable image. So, that process modified the partition table, and the drive now reports a size of 1Gb. Unfortunately, erasing or reformatting the drive doesn't fix it. From what I've read, I need to completely nuke the partition table. Usually, this would be very easy to do on a Linux machine, but I must do it on a Mac right now. The Disk Utility app doesn't seem to have an UI for this. Is there another tool or set of commands I could use?

macOS Big Sur 11.3.1

Since some recent version of macOS (High Sierra? more precision needed here), Disk Utility stopped presenting by default physical devices. Thus users are protected against erasing their disks by error. I would say that MacOS is evolving to hide more and more risky functions to protect users (which is easier than to teach them the truth).

To recover the usual vision of devices and volumes, one has simply to open the left top View menu and select Show All Devices. In fact this Show All Devices will show all physical devices (disks, USB flash drives, SSD…) but not truly all volumes.

From there, you will see that actually your drive wasn't shrunk, but just the unique volume on it was defined to be 1 GB. By fully erasing your physical drive, you will destroy its actual partition and create a new volume of 32 GB.