Hi Aussie,
We've faced a similar issue in our indexing process. What we've done was removing all the special characters with a gsub method (our interface language to Elasticsearch is Ruby):
content = content.gsub(/[\“\”\"\'\\\']/m, ' ').gsub(/[\n\t\r]/m, ' ').gsub(/\s+/m, ' ').strip
Hope it works for you!
Guilherme