> I never tested anything like this, but I think it works if you \protect
> the inner declaration like
>
> \footnote{foo  \protect{\foo{foo}} foo}

it's bad enough using the latex list for non-latex-research issues,
but to post clueless rubbish to it is worse still.

for the record:
1. \protect protects the next token (in your case "{"); to protect
\foo, say \protect\foo, with no braces around it.

2. \protect has no effect on the working/non-working state of \verb.
when lamport says in his manual that you can't use \verb in the
argument of a command, he actually means what he says.