That doesn't sound right to me. Both my rear calipers both wound in the same way. The wind in tool contains a threaded bar, it will only wind in one way and I only needed one tool to do both sides.
There's no reason for them to be opposing threads. This is the tool I have;
http://www.ebay.co.uk/itm/290697330910
Tool ordered,thanks very much for the advice and link.