Get your MND outta the toilet...sheesh.
Healing magic skills substantially quicker if you use Cure in offensive against undead. This is nothing new, but WHM is not normally much of a defensive job, making skill-up more of a "party" situation for us and as we all know, WHMs don't skill up in skill up parties, we haste people.
The advent of Abyssea has given us some handy tools in the way of skill ups and those are called atma that let us go skill up in the peace and solitude that we some times prefer. If you don't want to spent stones on skill, then use up some of your leftover time from events or xp there on skill ups.
In Attohwa [A] near the Martello at F-7 there is a cluster of bones called Schnitters. And bonus, they are not casters, saving us all the non-skilling downtime of managing mages. They con EM -DC at 90.
For atma, I used Mounted Champion, Vicissitude and MM. This gives you 37 HP a tick Regen, 16/tick Refresh(with coat) a stack of VIT and DEF. With a Terra's Staff and a jelly ring, their melee hits were landing in the ~40 range, which allowed the Regen to stay ahead and allowed me to focus on the spam. IF you aren't staying ahead, sub something that let's you use ice spikes and the missed melee rounds will be more than enough to stay ahead of the damage without ever having to cast on yourself.
I made a macro with 6 lines of /ma "Cure" <t> <wait 6> and stood with my back to the mob and had at it. I would also toss in a Flash between macros to skill Divine Magic for Repose as I really like thse to stick wen I use it. The main thing to look out for is to Erase(or Haste) the slow from Horror Cloud as that will mess up the timing of the casts.
Expect 1-2 full levels per mob. Enjoy killing with kindness.
This is a no Schnitter.