I personally think they are two different things. Interestingly, this document that shows photos of different clutter levels seems to use them interchangeably.
https://www.hoardingconnectioncc.org/Hoarding_cir.pdf
Maybe clutter is the stuff and hoarding is a behavior?
Jury is still out on the citrus smell. Boiling an old lime didn't produce a lot of scent so I will pick up a candle on my next shopping trip.