\usepackage{lua-check-hyphen}
...
\LuaCheckHyphen{mark,whitelist={filea.txt,fileb.txt}}

It lists all hyphenated words in the log file as well as in the file with the extension .uhy

A typical workflow is:

• run final document
• put the correctly hyphenated words into a text file (format: each word separated with space or on a single line, only whitespace matters as a separator)
• add that file to the whitelist (as given above)
• optionally use the option mark to make the unknown hyphenated words visible in the PDF file

Copyright 2012–2018 Patrick Gundlach (patrick@gundla.ch) and other contributors (see github)
Package version: see Makefile
Public repository: https://github.com/pgundlach/lua-check-hyphen
Licensed under the MIT license. See the file 'mit-license.txt' for exact terms.
Status: works fine, slightly unmaintained.