As some people in the comments pointed out, there are some places that might work even better. I suggest looking at those as well. Also thanks for the replies people, I'll keep this guide up so there is a good place for people to get this info.

I guess this achievement can be done in a lot of levels, but after searching a bit I found level 4-1 (Desperate times) is my favourite. It can be completed quickly and should fry about 5 worker droids every run.

What to do? Use the orange worker droid on the left panel to open the left door and release the purple worker droids and send them to their impending doom. At the same time stand on the right panel to do the same for the green worker droids. Next you need to stand in the door to the exit, turn around and make the wall next to the green panel orange as well. This way the orange worker droid will also be sacrificed for our glorious achievement hunt. Just make sure to walk to the right side of the door to get to the exit.

Rinse and repeat untill the achievement pops up.

In my case I had to shut down the game in order for steam to update the achievement progress, so if it doesn't show restart the game. Steam will update as soon as you get the achievement, so if you don't care to see your progress, you can just keep going.

English is not my native languages, so let me know if I made some stupid errors okay? XD