It's best just before you go to sleep, because in the day we are constantly washing our hands, getting stuff on them, wiping them, etc, so it's hard to keep the seeds on for long enough to really interact with our energy.
I use micropore medical sticking plaster stuff to actually stick the seeds on. You need something fairly sticky, to keep them on overnight. When you wake up, take them off in order, and just note which ones cracked, or if there's a big indent in your skin (which is another sign that the BODY is very depleted in that area.)
Then take that info into a personal prayer session, and see what happens.
If you try this at home, and you feel like sharing your experiences, feel free to post a comment.