find usb with command :
diskutil list
where /dev/diskN is a usb devices ( es. /dev/disk2)
unmount disk without ejecting by command:
diskutil unmountDisk /dev/diskN
move on folder with iso file inside and write
sudo cp -X ./isofile.iso /dev/rdiskN
waiting until the process copy al iso on usbdisk
eject the usb
enjoy
