This seems an appropriate place to share my experiment on Iris magnifica seeds.

Hopefully you can see eight pots in the picture. The four on the left were 2007 seeds (stored in fridge over winter) on the right, fresh 2008 seeds, all sown in October 2008.
The four back (top) pots were a soiled based compost, the front (bottom) peat based (previously used, no prizes for spotting the cyclamen that has decided to germinate now).
The two pots on the left in the year groups had part of the seed lightly cut off the others did not, none of the seeds were soaked. Is that all clear as mud ?!
The number of seeds germinating in 2009 were :-
11 2 5 1
13 8 11 5
This year I had :-
11 7 5 7
12 9 11 14
So I had no new germination from the seeds that were cut (I actually lost one) but the uncut seeds have germinated more and this is also true of seeds I planted in 2007 as I have had new germination in these pots which were again uncut.