I use dental floss.

This is dental floss I bought at a pharmacy. It's fine and unscented. I think it was around 3,000 won? Anyway, the price was more expensive compared to other places. I think it was because it was a pharmacy.

The dental floss is decent and easy to use. The case is sturdy, and the floss itself is soft. Since it effectively removes food debris that a toothbrush cannot completely take away, I recommend using dental floss for oral care.