When I worked at kilo scale, it was still pretty easy to lift the overhead off the flask and manually clean the reactor. (Note: when you have a narrow opening and you've dropped something in the bottom of your 72 L flask, find the coworker with the narrowest bicep.) When you get to much larger scale though, cleaning gets a little more mechanized. Enter the sprayball, which can be designed to spray solvent in all directions. These are pretty fun little gadgets (see the video above).
I don't know what I was expecting, but I'm glad the chemical engineers thought of this. There go my designs for a 100 liter acetone squeeze bottle with a 2 inch nozzle.