ATDocument programmatically replace in TextField

Dear, we have lot's of ATDocuments with OCR'ed content which was manually formatted through the editor in a 4.3 instance.

In the body-text of the documents some character-replacements should occur. So we have a browser-view available to read the documents body content via dokument.getRawText(), modfiying and writing it back with dokument.setText(). The Problem is, that the mxTidy validator kicks in and messes with the manually formatted tag information (css-attibutes).

Is there a way to disable the validator while executing the browser-view?

Thank you for any advice.