I was wondering if this cheese was doable: Take a copy of your save game while only
having ingested two or less One Third of Umbilical Cords.
Then go into the end game as accept Gehrman's offer thus ending the game and getting one achievement. After that, restore your save game and refuse Gehrman's offer thus ending the game and getting another achievement. Finally, restore the save game once again, and get to the true ending thus getting the final ending achievement.
Clearly, this is 100% pure rotting cheese. However, is it possible to do this?