This might be too late since it circulated a lot, but the 'Hanga Dýra Mingja' part isn't actually 'Hanga Dýra Mingja'. It supposedly was old Icelandic but it makes no sense grammatically and the word Mingja does not exist in Old Icelandic. It's more likely to be 'Hangatýr Hamingja´ and then after chanting that a couple of times they say 'Ramr'. It makes more sense since it is a healing song, Hangatýr is Óðinn who is mentioned in the Merseburg incantations, Hamingja is Luck and Good Fortune in Old Norse, as well as a sort of guardian spirit, kind of. Ramr is strength in Old Norse. So really they are chanting ''Hanging God, Spirit of Fortune (bring) Strength'' Makes sense calling on them for healing, rather than hanging animals, I guess

Goes kind of like this

Hangatýr Hamingja
Hangatýr Hamingja
Hangatýr Hamingja
Hangatýr Hamingja
Hangatýr Hamingja Raaaaaaaaammmmmmmmrrrr!

@benjaminjonsson7129