Looking at my Cleric spells it's just a guess, but I'm thinking positive karma is a factor...one spell, "Angel Faith", turns your character into what is described as a holy angel. Other wording, such as, Sacrifice, Smite and Sacred seem to denote a positive karma. Maybe you could borrow a book from a friend and try out "Repurgo", (the purge spell), after you curse & poison yourself--it should remove both at the same time, (pink flame graphic). But if it relies on positive karma it may either do nothing or hurt you. It's a great spell to have as it removes the toughest curses and poisons at once.