Word – How to add obfuscating stripes to a PDF or Word document

I wish to take a PDF or Word document and run stripes through the text to obscure it so that complete confidential information is not revealed, but one could compare against an unstripped other file to detect whether the unstripped version was a copy of the original file in at least some parts.

How can such stripes be added? I searched Google and couldn't find anything using the terms like stripe pdf tool obfuscator. I created a zebra stripped PNG file like this:

But using it as the watermark in Microsoft Word 2011 without any washout gives grey strips that reveal the text underneath. Exporting to PDF does show in Adobe as black stripes, however, the text under the black stripes remains and can still be copied, for security, I'd like to convert the file to an image based PDF and not contain any text under the black stripes. I tried exporting images from PDF, but that only gave me the zebra stripping, no image of the text. I don't want to just print it all out and scan it back in again due to the document being 1,500 pages long, and so do not want to waste the paper, nor deal with scanning that many pages.

Taking the PDF exported from Word with Zebra stripes, I can select a single character under the zebra stripes on each page of the document for redaction, once I've touched every page, I can then apply the redaction and remove hidden information to convert each page to an image of the page, no text remaining.

While this works, it requires each page to be touched to redact at least a character on each page in order for Adobe to convert that page to an image.

Is there an easier way to tell Adobe to convert each page to an image of the page without having to touch every single page?