Sidechaining using 3rd-party plugins

I’m trying (and so far failing) to figure out how to set up sidechaining for 3rd-party plugins in Cubase 7.5.
There’s a step-by-step guide here but I can’t get it to work:

I’ve even tried following the above steps for one of the Cubase compressors with a sidechain button that I know will definitely work using the normal method but even that won’t work. To summarise I’m doing the following:

  1. Press F4 and create new FX bus for compressor with Stereo and Stereo (Ls Rs) child busses
  2. Go to Audio Sends on track to be used as trigger (e.g. kick) and route it to the Stereo (Ls Rs) bus of FX channel
  3. Go to Audio Sends on track to be compressed and route it to Stereo bus of FX channel
  4. Enable sidechain on compressor in FX channel

Can anybody help?