ADB pull error: remote object '/dev/block/mmcblk0p24' not a file or directory
adb pull is for files.  /dev/block/mmcblk0 is a block device.  user1133275's answer to that question doesn't work; try the other one, i.e. run adb shell and then:

$ su
# dd if=/dev/block/mmcblk0 of=/sdcard/something.bin


Then you can run adb pull /sdcard/something.bin.