I am no expert in alternative medicine, but deer penis was ingested by the ancient Greeks for sexual issues, and given the wide range of alternative medicines that have been used in China for millennia—of course there it wouldn’t be considered “alternative”—it wouldn’t be surprising that horse penis would be considered helpful in one or more specific medical conditions.
In other news...
https://en.wikipedia.org/wiki/Chimney_Rock_National_Historic_Site#History