Does this include the following?
- Reading some words/digits in the online computer.
- Walking to the airgapped one.
- Manually typing the memorized words/digits on the keyboard.
Yes, even those methods are not safe strictly speaking. Theoretically a virus can trick you into recording the wrong data. A truly safe cold storage device can only ever safely transmit data out of itself, never receive input data, as such input data can never truly be guaranteed to be secure.