Adding ``This page was intentionally left blank.'' placeholder page in twoside document

Question

I wish to add placeholders into my disseration to ensure that all chapters begin on an odd page. These placeholders should contain ``This page was intentionally left blank.'' printed in the centre of the page. I'm using the document class:

\documentclass[a4paper,12pt,twoside]{report} 

and within my latex code preamble I have placed the following:

\makeatletter
\def\cleardoublepage{\clearpage\if@twoside \ifodd\c@page\else
    \hbox{}
    \vspace*{\fill}
    \begin{center}
        This page was intentionally left blank.
    \end{center}
    \vspace{\fill}
    \thispagestyle{empty}
    \newpage
    \if@twocolumn\hbox{}\newpage\fi\fi\fi}
\makeatother

which I found on a previous post https://latex.org/forum/viewtopic.php?t=20410. However, this code snippet doesn't appear to have the desired outcome. I've also tried the hack How do I make pages which were "intentionally left blank"? but this doesn't appear to work either.

Answer 1

Managed to get it to work, just had to change:

\documentclass[a4paper,12pt,twoside]{report}

to

\documentclass[a4paper,12pt,twoside]{book}