Upon finding a cadaver, SCP-550 will unravel itself to create a wide split in the area where a chest would be, and will kneel over and make contact with the cadaver. This cavity does not appear to be different from SCP-550's exterior, and it secretes high concentrations of hydrochloric acid.
The hydrochloric acid it produces is used in breaking down organic substances located in corpses, allowing it take in nutrients through pores in the wood it is composed of.
This is pretty much what it does. I can rephrase it a bit, I think.
Several ritualistic items such as incense and candles, along with pieces of a large cloth and various salts and spices were found scattered throughout the graveyard.
Hint, for why there's a tongue. I changed it from a quilt and just various spices to the bolded area.
And no, the cult was not responsible in screwing the guy up. They were trying to help the guy, though mostly for personal gain. I don't think anyone else ever would want what they wanted to happen to themselves (another hint: they're dead). I would prefer to leave the curling up part in, since I think the Foundation would come to that conclusion with all the background info.