I agree with that for sure.
Just a note, though...  The Arnica I took was in a pellet form and 
prior to surgery.  Its intended purpose was to minimize bruising and bleeding.
I've seen some post-op pictures that made me kinda queasy because of the severe bruising.  Mine was very minimal.....almost nil, honestly.  And I didn't have the excessive drainage issues either.
Not saying all who use Arnica as a pre-surgical supplement will get the same results, but I don't think it'll hurt to try.