Omnistat remote temp sensor install

Has anyone tried to install the remote temp sensor without using a shielded cable? I have a short run (~10 ft) between the stat and the sensor, and was planning on tieing into an unused pair from the cat5 I ran between the stat and the OPII, but it is just standard unshielded cat5. Would make the install quite a bit easier if I didn't have to run a new wire...

I tested the remote temperature sensor with some 15 feet of 22/2 alarm cable and it worked fine for me.  Never tried using an unused pair of utilized cat5 for something like this before.