First, the dental floss mod is where you put a 1 cm length of dental floss in the spring of a buckling spring keyboard to quieten it.
Retr0-brite is a process of mixing harsh chemicals (especially bad for the eyes) and exposing the plastic to sunlight.
Apparently, a couple of decades ago, it was popular to mix bromine into ABS plastic for fire-retardance, and it caused the plastic to yellow over time.
I have tried it several times with a couple of resounding successes, several partial failures, and many total failures.
The trick is probably getting the chemical mixture into a nice gel that does not dry too fast, and exposing it to good strong sunlight for several hours.
As far as removing pad printing, you will probably have to abrade it. If I were doing it, I would use my electric eraser, but I am an old man and only an old-school architect, draftsman, or artist is likely to own one, so try a buffing pad on your Dremel instead.