Reading .docx files for the truly paranoid: unzip -p ./foo.docx | sed -e 's/<[^>]\{1,\}>//g; s/[^[:print:]]\{1,\}//g'

— Halvar Flake (@halvarflake) September 30, 2016

Well, as a truely paranoid guy i would not use unzip, because the code base is not maintained anymore and probably kind of sketchy.

Update

I turned this into a go program, which is available from gitlab.com/scusi/paranoiddocx.