IN CONVERSIONS

That seems to be a great way to

the document
Maybe in the Editor, where you could Find > Replace-Next or Find (again)
Just some ideas:
You can have a list of words to match
Code:
(word1|word2|word3)
But I don't know how you word calculate the replacement.

(if no one comes up with a better way) Use the Spell checker (in the Editor) ALL WORDS showing:
Find
your word on the left, type Your Replacement: Apply that
<repeat for each word>