This script allows you to count number of symbols in batch of docx files excluding white spaces and new line symbols. Just place this file into the folder with docx file and run in terminal 'sh count_symbols_in_docx_file.sh'

count_symbols_in_docx_file.sh

#!/bin/bash
for file in *.docx;do
  number=$(unzip -p $file word/document.xml | sed -e 's/<[^>]\{1,\}>//g; s/[^[:print:]]\{1,\}//g'|tr -d ' '|tr -d '\n' |tr -d '\t' | wc -m | tr -d ' ' | tr -d '\t')
  echo "File -> $file , symbols count: $number"
done