# Changing position of footnoterule partway through document

I am compiling my thesis as a memoir class, and the final chapter has two different kinds of footnotes. I want the footnote rule to appear between the two different kinds of footnotes, whereas in the main text the line appears between the footnotes and the body.

In order to get this to affect only this section, I have redefined the footnoterule command at the appropriate spot, like so:

\documentclass[12pt,twoside]{memoir}

\usepackage{bigfoot}
\DeclareNewFootnote[para]{B}[alph]
\DeclareNewFootnote{default}

\renewcommand{\thefootnoteB}{\emph{\alph{footnoteB}}}

\usepackage{alphalph}
\renewcommand{\thefootnoteB}{\emph{\alphalph{\value{footnoteB}}}}

\usepackage{perpage}
\MakePerPage{footnoteB}

\begin{document}

\mainmatter

This is text.\footnote{Footnoted.}
\newpage

\let\extrafootnoterule\footnoterule
\renewcommand{\footnoterule}{}

Here is some more text.\footnote{With a footnote.}

And some other text.\footnoteB{With a fancy footnote.}

\end{document}


However, as I show here, this means that while the new footnote rule correctly appears, the original dividing line is still sticking around! What can be done to eliminate it or make the new rule more effectively replace the old one at this point?

The package bigfoot (actually it's manyfoot) changes the way the footnote rule is typeset and uses \defaultfootnoterule.

\documentclass[12pt,twoside]{memoir}

\usepackage{bigfoot}
\DeclareNewFootnote[para]{B}[alph]
\DeclareNewFootnote{default}

\renewcommand{\thefootnoteB}{\emph{\alph{footnoteB}}}

\usepackage{alphalph}
\renewcommand{\thefootnoteB}{\emph{\alphalph{\value{footnoteB}}}}

\usepackage{perpage}
\MakePerPage{footnoteB}

\textheight=4cm % just for the example

\begin{document}

\mainmatter

This is text.\footnote{Footnoted.}
\newpage

\let\extrafootnoterule\defaultfootnoterule
\renewcommand{\defaultfootnoterule}{}

Here is some more text.\footnote{With a footnote.}

And some other text.\footnoteB{With a fancy footnote.}

\end{document}


(I set the text height just to minimize output.)