I know I am late to the game here, but I am running this in 2 weeks for the first time and I wanted to check up on two points (by the way, thanks to everyone for the clarifications in this thread - it is going to help running this A LOT!). Let me know if these are correct - if not, please correct me:
1) There is no net gain in ability scores if a PC participates in the ceremony and then eats a wafer. For example, a PC participates and is hit for 2 points of ability score - let's say 1 INT and 1 STR (player's choice). They then have 2 choices if they decide to eat a wafer:
a) Eat their or and return their ability scores to their previous levels and incur no profane penalty and not have to atone; or
b) Eat another's wafer and receive 2 ability points to any one score - for instance, in my example, they may choose to take 2 in STR, and end up down one in INT and up one in STR - they then have to atone if they are moved to evil.
2) Atonement - since they know it is an evil deed, the spell requires a 2500 additional component - that is over and beyond the cost of the spell as a service in PFS.
Hopefully these are both correct - if not, please let me know! Thanks