Installing TWRP on Xperia running CM11

I've got an Xperia Z2 running CM11, and would like to switch to TWRP as my recovery. TWRP's website has the instructions I followed for this device.

It states that "if you install current CM10 and CM10.1 nightlies and flash TWRP to the FOTAKernel partition, you will be able to use TWRP instead of the CWM that normally comes in a CM boot image" (I'd be amazed if this worked for CM10 and not CM11?)

I have downloaded the 2.8 openrecovery***.img file to my sdcard, and followed the instructions -

adb root
adb shell dd if=/storage/sdcard1/FILENAME.img of=/dev/block/platform/msm_sdcc.1/by-name/FOTAKernel

adb output:

23828+0 records in
23828+0 records out
12199936 bytes transferred in 1.579 secs (7726368 bytes/sec)

So adb seems to think it worked, and dd seems to think it found something called "FOTAKernel" to overwrite.

Reboot to recovery, and no sign of TWRP, it still puts me into CWM. What am I doing wrong?