Thanks to ZorkiKat, it is also possible to make a version of PaRodinal which is clear, unlike the version on digitaltruth.com.
http://photo.net/black-and-white-pho...g-forum/00UxmB
I just tested a sample of the clear version 15 months old with the "dab test" ,it still works OK although the bottle is now only 20% full.
Interestingly, this initially clear version now has crystals in it but I do not know what they are.