I think I'll give this a try. It's interesting because my standard method for roasting
a chicken on a hunting or camping trip is to place the cavity over a stick near
the fire and rotate as required to cook procgiy. The birds turn out much dryer
than the ones I do in my kitchen; so I've always been skeptical of those
vertical roasting gadgets.

But this is different because the can offers the chance to catch at least some
of the natural juices. And whatever you decide to put in the can before
roasting, could be re-absorbed into the bird during the resting period after
roasting.

The only suggestion I can give you would be to leave the can in until just
before serving so the bird can absorb as much of the liquid as possible.

As far as what goes into the can; I'd be here all night.