Im no master macro maker myself either. But since rejuvenation calls for a globalcooldown (and equipping idols?) you must klick the macro several times to execute every line.
Do not matter how much you play, you will never get the carrot.
I made macros to do these on every cast as initially it seemed to not use GCD.
However when I finally macro'd it all up they ended up messing about with the GCD and I was unable to get cast on click with Lifebloom or Rejuv, always had to click 2-3 times.
Macros CANNOT get around the global cooldown, don't even try. In particular, be aware that switching a weapon (i.e. anything that goes into one of the lefthand, righthand and ranged weapon slots) always trigger a 1.5 s. global cd in combat. This also includes idols.
The problem is the GCD triggered by weapon swaps. However, if the spell has a cast time, you can swap weapons while casting.
For instance
/cast healing touch
/equip Idol that buffs healing touch
will work, instants will not since they don't have a cast time. +Heaing is calculated on spell cast, so equiping idols after you start the cast time is what you want to do.