I SHIFT-A them. (This is usually not until well into the Industrial Age. I generally make sure all my cities are connected by rail-road before I SHIFT-A them, but if I'm feeling lazy, I might do it earlier.)
Sometimes I hit the CTRL-A instead by mistake; then the stupid worker will start changing what I've already done. Eventually I find it and assign it it's proper orders.
If you need a specific task done, it's not bad to find a few doing whatever they're doing, re-activate them by clicking on them, and order them as you wish; then re-automate them afterwords. And the native workers ARE good for joining to cities if needed.
Sometimes I hit the CTRL-A instead by mistake; then the stupid worker will start changing what I've already done. Eventually I find it and assign it it's proper orders.
If you need a specific task done, it's not bad to find a few doing whatever they're doing, re-activate them by clicking on them, and order them as you wish; then re-automate them afterwords. And the native workers ARE good for joining to cities if needed.