Wouldn't Rodney have some possessions? It's kind of annoying to live in a human society penniless, even if you are an undercover demon, or actually especially if you are an undercover demon who doesn't want to lose the cover. I don't see why the MC dude wouldn't be able to loot that mansion Rodney was using and even check Rodney's room back at the church. He defeated the demon, so everything the demon owned now belongs to him.
But then again, the Japanese absolutely and unconditionally love the destitute hero trope, so of course the MC wouldn't go and collect any coins and valuables.