Making PDF's word searchable?

Hello,

I redact documents and they have to be word searchable.  I an using Adobe Acrobat DC and tried using the Scan OCR option in tools, Reconize text, all pages, and then click OK but it still gives me the message no words found even though I know I used a word that is on multiple pages.  

Any help would be greatly appreciated.

Thank you,

Kathy