And the point in that exercise in futility is what, exactly?
I saw really bad lettering executed using a most amateurish technique. With work of that scale generally one does not strike in and then fill. If you can call what they did striking in. You select the proper brush or nib or whatever and do it with as few strokes as is necessary. The more strokes, the cruder the result. The specimen doing the work in that clip gave every appearance of being someone's nephew who can draw.
That very same job if done by an actual professional would only have needed token cleaning up. The characters would have been properly formed**, the edges would have been crisp as well as the corners, and the fills would have been without holes.
**The instrument you're using, be it brush, pen, or a finger dipped in mayonnaise, forms the character stroke by stroke. You don't sketch at it, you set the instrument down on the media and move it. The more confidently you move it, the better the result.