Are there are means for clerics to cast spells with incompatible alignment descriptors?
I can think of two possibilities. The first is creating a spell that temporary switches the caster's alignment. The second is using UMD to fool the spell—but the exact wording of the UMD rules makes me skeptical that that's a valid use.
So, can I build a slippy cleric?
Small update: I search for the cheapest way to turn any outsider with the turn anathema spell. But there are other helpful usages, such as summon monster.
After reading the answer I have impression that investing skill points into UMD and having some scrolls in the equipment list would be the easiest way.