I have used the Blood Statuette regularily for both 6th and 7th edition Lizardmen now. It is too bad it no longer ignores ward saves, your best bet is to apply it to a T3, 2 wound character so you have a 50% chance of getting half points for that character (barring wards). Hero Mages are even better as they have a chance to kill themselves afterwards with a miscast.
I'd say the best targets would be in this order:
1) TK Hierophant (regardless if it is a Liche Priest or Liche High Priest)
2) Enemy Skink Priest
3) Hero Level Wizard (Empire Wizard, Wood Elf Spellsinger, Dark Elf Sorceress, High Elf Mage, Skaven Warlock Engineer, Goblin Shaman, Brettonian Damsel)
4) Any T3 BSB (High Elf, Dark Elf, Wood Elf) or a revealed Dark Elf Assassin or Skaven Assassin (assuming they are T3 which they may not be)
5) Any 2 wound T4 Wizard (Orc Shaman, Chaos Sorcerer, Dwarf Runepriest) or Daemon Herald other then Herald of Khorne (due to MR)
6) 3 Wound Lord-Level Wizard or T4 BSB
Anything else is just bound to waste your points (Tomb Prince or King, Scar-Veteran or Oldblood, Any Lord level fighter character, Any type of Orc fighty hero, Ogre Characters, Slann Mage-Priest, Greater Daemon, etc.) not only due to the fact that the Statuette will not remove them from the battle, but potentially will not even wound them. In addition fighter characters are much more likely to have Ward Saves and Regeneration which the Statuette no longer ignores.
I usually use the Statuette in my magic heavy list (Slann Mage-Priest with +1 die per spell, know all spells from 1 lore, and Regeneration, level 1 Skink Priest with Plaque of Tepok and the Statuette and Level 2 Skink Priest with Rod of the Storm and Dispel Scroll)
After I use the enemy dispel dice in the first turn I usually pop the Rod of the Storm at a unit of Knights, thus causing them to scroll it or let it go. I pop the Statuette immediately after and see if I can kill any Wizards to help my magic phase in the next turn. I do see the idea of leaving these items for Turn 3 or 4 when the scrolls may be gone but I figure if they scroll the Bound Spells then we are even in points and my Slann will have an easier time for the rest of the game. Plus if they do manage to kill a character then I see the benefits from Turn 1.