How to inline complex grep call into git config

Question

I have, following this answer, created an executable file "podiff" for use as a custom diff (and later, hopefully, a filter) calling grep in this way:

grep -Ev '^#:|^"POT-Creation-Date|^"PO-Revision-Date|^"Last-Translator' $1

It dutifully seems to omit all the changes in metadata which are uninteresting when using any version control system.

Unfortunately, it would seem that in addition to a .gitattribute entry I also need an extra .gitconfig file to be manually included in .git/config to allow this behaviour to itself be version-controlled.

Can I somehow inline the podiff file into my .gitconfig file at least?

This more primitive entry works inline:

[diff "podiff"]
    textconv = "grep -Ev '^#:'"

but I have not found a way to make the full expression work.

Entering manually or via git config --add

textconv = "grep -Ev '^#:|^\"POT-Creation-Date|^\"PO-Revision-Date|^\"Last-Translator'"

results in the full diff, no lines omitted.

textconv = "grep -Ev '^#:|^\\"POT-Creation-Date|^\\"PO-Revision-Date|^\\"Last-Translator'"

results in "fatal: Invalid configuration line 2 in file .git/../.gitconfig".

X/Y answers:

This answer suggests using gettext-specific tools instead of parsing the generated file "manually". However, it would seem that msgcmp cannot omit such lines at all and msgcat can only omit specifically usage comments, not the rest. (Etc. for the other tools.)

Presumably it would be best to suppress the generation of the bothersome lines in the first place, but e.g. the MonoDevelop GetText plugin that some of my colleagues use does not offer any configuration options at all, nor does another such tool, Poedit.

Is there a better way?

(Including "just keep your hands off gettext" or "you actually can inline the .gitconfig entry into your .gitattributes and keep the podiff file instead".)