/etc/rc shebang

I was wondering whether I could have /etc/rc being executed by another shell 
(/rescue/sh).

I know /etc/init called /bin/sh /etc/rc back in the day, but things may have changed.

init(8) says "Executes /etc/rc". /etc/rc has #!/bin/sh. But sbin/init.c has
	argv[0] = "sh";
	argv[1] = _PATH_RUNCOM;
	argv[2] = (runcom_mode == AUTOBOOT ? "autoboot" : 0);
	argv[3] = 0;

So I guess the manpage should be re-phrased.

Any better idea for using an alternate shell than exec /rescue/sh <<EOF?

(In case you are wondering why on earth I want this: updating things which 
will move around /bin/sh, /lib/libc* etc.)