Copy Crucial SSD Firmware Update ISO to Bootable USB

I want to start with the [Crucial SSD Firmware Update](http://www.crucial.com/support/firmware.aspx) and copy the ISO to a bootable Mac USB stick, using a minimal set of tools. I hope that means using only built-in Mac software, such as Disk Utility and Terminal for commands. If necessary, I will reluctantly use a commercial tool. (As of this writing, the latest is [Crucial_m4_040H-04-00.zip](http://edge.crucial.com/firmware/m4/040H/Crucial_m4_040H-04-00.zip).) I've have waded through a muck of articles about how to copy an ISO to a bootable USB stick, but I have not found a solution that works and that I'm comfortable trying. * For example, I read [How do I burn an ISO on a USB drive on Mac OS X?](https://superuser.com/questions/63654/how-do-i-burn-an-iso-on-a-usb-drive-on-mac-os-x) and followed the steps. The steps seemed to work, but the resulting USB stick would not boot. I tried two different sticks to reduce the chances that it was a hardware issue. * I've also read [Updating firmware on Macs without a superdrive](http://forum.crucial.com/t5/Solid-State-Drives-SSD/Updating-firmware-on-Macs-without-a-superdrive/td-p/61259) too. One part recommends using [rEFIt-Syslinux.dmg_.zip](http://blog.io101.org/wp-content/uploads/2011/04/rEFIt-Syslinux.dmg_.zip) . But how do I know if that DMG is up-to-date, reliable, and trustworthy? Even if it is, that route seems unnecessarily complicated. Why is there not a simpler option?