I found this splitter on forums where people want to record the HDMI output of playing games on consoles. Many of these are HDCP protected so can't normally be recorded using HDMI capture cards. This splitter is the cheapest device those forums list that will strip the HDCP for you. Also if you read the amazon.co.uk and amazon.com reviews for this splitter you will see many people recommending it for stripping HDCP to record HDMI output.
I realise there is still an HDCP handshake between the splitter and the DTR-T1000. Hopefully that handshake will work. What this gets rid of is any subsequent HDCP handshake out to the TV, so the troublesome combination of my TV and DTR-T1000 is avoided. Actually anything which regenerated the HDCP might have done the job but would have involved two HDCP handshakes as you say. With this device I don't introduce a second handshake.