let me preface this post by saying that I'm only casually familiar with biodynamic methods. I don't even know what exactly biodynamic barrel compost is. onward.
I've seen a few comparisons (no references, just vague recollections. sorry.) of biodynamic operations to conventional and organic operations. the biodynamic operations generally came out on top, but not always definitively so. none of the comparisons that I can recall set up control groups et cetera as per scientific method.
biodynamic practices don't seem to lend themselves well to objective observation. it's difficult, for example, to determine the amount of cosmic
energy my broccoli contains. I'm not such a strict adherent to the religion of science that I would dismiss out of hand the importance of cosmic energy for growing good broccoli, though.
I would be interested to see comparisons between full-fledged biodynamic agriculture with a sort of half-assed biodynamic agriculture. maybe use the same raw ingredients, but skip the cow horn. or use the cow horn, but don't bury it as deep. or spin things the wrong direction. there's very little doubt in my mind that some pretty good ideas are contained in these practices, but I'm skeptical of the more ritualistic aspects. I think the rituals could potentially have positive effects on our attitudes and relationship to the dirt even if they don't have any
concrete benefits, but dogmatism in any form makes me immediately suspicious.
I think a trial at home is worth a shot and you
should go for it.