what about sky burial? though i dont know is there a big carrion bird that can eat whole bone though in europe, so maybe the crow or other small flying carrion can suffice to left the bone intact, at least majority part of it.
you can also build tower to place the corpse there to make it out of human contact live bellow and not spreading the miasma if no mountain, and not necessary for you to grind the bone like some of this culture do if you want to keep the bone intact.
Sky burial (Tibetan: བྱ་གཏོར་, Wylie: bya gtor, lit. "bird-scattered"1) is a funeral practice in which a human corpse is placed on a mountaintop to decompose while exposed to the elements or to be eaten by scavenging animals, especially carrion birds. It is a specific type of the general practice of excarnation. It is practiced in the region of Tibet and the Chinese provinces and autonomous regions of Qinghai, Sichuan and Inner Mongolia, as well as in Mongolia, Bhutan and parts of India such as Sikkim and Zanskar.2 The locations of preparation and sky burial are understood in the Vajrayana Buddhist traditions as charnel grounds.
The tradition and custom of the jhator afforded Traditional Tibetan
medicine and thangka iconography with a particular insight into the
interior workings of the human body. Pieces of the human skeleton were
employed in ritual tools such as the skullcup, thigh-bone trumpet.
The 'symbolic bone ornaments' (Skt: aṣṭhiamudrā; Tib: rus pa'i rgyanl
phyag rgya) are also known as "mudra" or 'seals'. The Hevajra Tantra
identifies the Symbolic Bone Ornaments with the Five Wisdoms and
Jamgon Kongtrul in his commentary to the Hevajra Tantra explains this
also here excarnation some copy paste method to defleshing maybe it can help (some contain burial and cremation method though).
From the pattern of marks on some human bones at prehistoric sites,
researchers have inferred that members of the community removed the
flesh from the bones as part of its burial practices.
Neolithic farmers living in Tavoliere, Italy, over 7000 years ago
practiced ritual defleshing of the dead. Light cut marks suggest that
the bones were defleshed up to a year after death. The bones were
deposited in Scaloria Cave and, when excavated, were mixed with animal
bones, broken pottery and stone tools.
In the Middle Ages, excarnation was practised by European cultures as
a way to preserve the bones when the deceased was of high status or
had died some distance from home. One notable example of a person who
underwent excarnation following death was Christopher
Columbus. The American Revolutionary War general,
Anthony Wayne, also underwent a form of excarnation. A practice
known as mos teutonicus, or active excarnation, was a German custom.
The bodies were broken down differently than solely defleshing, they
were cut up and boiled in either wine, water, or vinegar.
In modern Japan, where cremation is predominant, it is common for
close relatives of the deceased to transfer, using special chopsticks,
the remaining bones from the ashes to a special jar in which they will
be interred. However, in ancient Japanese society, prior to the
introduction of Buddhism and the funerary practice of cremation, the
corpse was exposed in a manner very similar to the Tibetan sky burial.
The Kalash people of Pakistan until recently (mid 1980s) practiced
above ground burial in large wooden coffins called Bahg'a were the
dead were laid with all their best belongings in cemeteries called
Madokjal or place of many coffins. This tradition had been dying off
with the last being the burial of a shaman in 1985, until the burial
in 2016 of Batakeen of Anish village Bumburet. The Bali Aga people of
Trunyan village on Lake Batur in Bali practice customs found no where
else on the island, these are the mountain Balianese and they practice
Animistic traditions that predate the arrival of Hinduism in Bali. The
burial custom here is for the bodies to be laid on the ground and left
to decompose, with a cloth cover or a bamboo cage . Once the
decomposition is complete the bones are placed on a stair shaped altar
500 feet to the north. A large banyan tree called the taru menyan
literally called the nice smelling tree is thought to take away bad
smells . Pre-contact Hawaiians ritually defleshed the bones of
high-ranking nobles (ali'i) so that they could be interred in
reliquaries for later veneration. The remains of Captain Cook, who the
Hawaiians had believed to be the god Lono, were treated this way after
his death. The Moriori people of the Chatham Islands (now part of New
Zealand) placed their dead in a sitting position in the sand dunes
looking out to sea; others were strapped to young trees in the forest.
In time, the tree grew into and through the bones, making them one.
Following the excarnation process, many societies retrieved the bones
for burial.
Defleshing during the Middle Ages
During the Middle Ages in Europe, defleshing was a mortuary procedure
used mainly to prepare human remains for transport over long
distances. The practice was used only for nobility. It involved
removing skin, muscles, and organs from a body, leaving only the
bones. In this procedure, the head, arms, and legs were detached from
the body. The process left telltale cuts on the bones.
King Saint Louis IX of France is said to have been defleshed by
boiling his corpse until the flesh separated from the bones. This was
intended to preserve his bones, to avoid decaying of the remains
during their return to France from the Eighth Crusade, and to provide
relics. The process is known as mos Teutonicus.