For a real solution to this, here's the _correct_ way to do it.
First, an explanation.
pure-ftpd-mysql calls a wrapper to the main command. That wrapper is pure-ftpd-wrapper, normally found in /usr/sbin.
In that file, you can see a list of the option/configuration files it looks for. One of which is TrustedGID.
If the user you wish to have granted full access (this must be a REAL USER, not a virtual one) is part of the adm group, for example, look up the GID in /etc/group for the adm group (4 is normal)
Then, you simply need to type 'echo 4 >/etc/pure-ftpd/conf/TrustedGID' and then reset pure-ftpd. Now, anyone in the adm group will be allowed the ability to break out of the chroot.
This is the actual answer to the initial question, rather than a list of workarounds, reasons for not doing it, or deliberate misunderstandings