MassNullEdit is based on several other scripts (NullEditButton, AjaxBatchDelete and ChatBlockButton), that provides a link to a modal (without changing location) which allows the user to list pages to be null edited.
Template:Script Instal
Usage
In order to null edit multiple pages, add the page names (not page URLs) each on a new line (including their namespace if necessary) and proceed to null edit them. The script will stop when it reaches an empty line.
If the script is used on Special:WhatLinksHere, it will automatically add the listed pages/files into the text area. Users may also add the contents of categories straight into the text area using the button.
By default, the script will do one page per second. If you'd like to modify that, add the config nullEditDelay before importing the script with your own number (in milliseconds) instead.
Monobook
The option to use the Mass Null Edit script will appear in your toolbox on the left.
Oasis
The option to use the Mass Null Edit script will appear under your "My Tools" list (the toolbar at the bottom of your screen).
Please note you must not have the toolbar at the bottom hidden or the script will not function. If you do not see the "My Tools" (or other language equivalent), try clicking Customize and then "reset defaults" to not hide the "My Tools".