Clear experiment diagram which explains that the droplet mass determined with Stoke's law:
Video 1. Quantum Mechanics 4a - Atoms I by ViaScience (2013) Source.
American Scientific, LLC sells a ready made educational kit for this:
Here's some actual footage of a droplet on a well described more one-off setup:
Video 2. Millikan's Experiment, Part 2: The Experiment by Phil Furneaux (2017) Source. From Lancaster University
This American video likely from the 60's shows it with amazing contrast: