The slugs are the metal pieces at the ends of the assemblies that start at the tops of the keys and go through the key levers attach to the segment (the semi-circular metal comb-like part in the "basket") via the typebars. The slugs are the ones that have the backward characters on them and when they hit the ribbon cause the letters to be applied to the paper. Over time the small loops of the characters can get filled with dust, dirt, ink, and bits of ribbon and as a result the type on your page isn't as crisp and good looking as you'd like.
Here's a handful of videos with a variety of methods for cleaning one's slugs:
- https://www.youtube.com/watch?v=2s8tE6P0YMQ
- https://www.youtube.com/watch?v=SgSAS45WGI0
- https://www.youtube.com/watch?v=jKGipBLA5Eo
You'll notice that for the day-to-day cleaning that people are using kneadable erasers, silly putty, or products like Bergeon Rodico 6033-1 as cleaning compounds for pulling ink and dust out quickly.
There are some good basics and a great glossary in Hints for a Happy Typewriter: https://typewriterdatabase.com/1983-Hints4HappyTypewriter.index.manual
I've also collected some great mid-century short films on use and basic maintenance here: https://boffosocko.com/2025/06/06/typewriter-use-and-maintenance-for-beginning-to-intermediate-typists/
Other resources you might find interesting: https://boffosocko.com/research/typewriter-collection/
reply to u/DatLonerGirl at https://reddit.com/r/typewriters/comments/1o33p7n/when_was_the_last_time_you_cleaned_your_slugs/