After extracting the archive you can write the bin file to a USB stick sector by sector just by using command line in OS X:
You'll then see something like this:
The device number (in this case 3) is what we are looking for.
We are first going to unmount the device from the operating system:
diskutil unmountDisk /dev/disk# (If we were following the example in the picture, we would replace /dev/disk# with /dev/disk3 here)
Now, we are going to block copy the binary image to the device:
sudo dd if=RDT-150507a.bin of=/dev/disk# bs=1m (disk# to disk3 again if using the example)
Once you get a prompt back, you can eject the drive:
diskutil eject /dev/disk#
You now have the Rapid Drive Tester (RDT) software on a USB stick. You can boot from it to enter RDT and test connected drives.