I tried the following to clear my cached credentials to no avail:
Later I noticed that I could open my personal notebook and browse my OneDrive files from the recently used files menu without a password prompt. While using OneNote 2016 (Office 365 ProPlus, Windows 10 1803) at work, logged in with my work LiveID, I needed temporary access to my personal OneNote notebook, so within OneNote I logged into my other account, retrieved the information, and closed the notebook.
Briefly: After logging out of all my Microsoft accounts in OneNote I was still able to open/browse OneDrive files, private to those accounts, from the recently used list.
