Yeap, I did.
Sam, when you add stat+ potions to your wisdom, assuming it isn't maxed at 20 (natural) then your grace will go up. The ammount of grace you have is generated by how much wisdom (stat) you have, and then the level of your piety [:
Also, if he parties with people and just prepares piety skills he will get experience if the other members in the party are killing animals using pity skills
So, this is the second way around the problem. As I said, it's based on wisdom (stat) and then piety level. You could max your wisdom (stat) or level your piety - either one will give you more grace.
So, the solutions we suggested should work :P