Check out this thread. It describes an apparently very successful way to root geraniums.

Geraniums should be easy to propagate from cuttings. I remove the lower leaves, stick them in the dirt, & place them in the shade.

I like your method ;-)

I've started to allow my geraniums to callous (simply to dry on the cut end,) for a day, then plant. I'm having slightly better success, less loss to stem rot. Of course, I'm still potting up indoors, as it is too cool for geraniums outdoors here.