I took a slightly different path which also fixed it. (My uninstaller had already removed the Saved Application state file)
There were two files in the
foldercom.kobo.desktop.Kobo
which itself was within several very random alpha-numeric strings inside
/private/var/folders/*
This is how I found that elusive folder. I used the handy, free
EasyFind utility from
Devon Technologies or the
Mac App Store
...and I searched for the string "kobo".
(I also ticked the following boxes:
SEARCH FOR
- Files & Folders
OPERATOR
- All words
COMPARISON
- Ignore case
INCLUDE
- Package contents
- Invisible files & folders)
Finally, I clicked on the "where" column to sort by location. I realized I could leave the files that contain "kobo" when they were Calibre tools, or the iPad Kobo app, or CrashReports, or any browser cache page.