Allowing Gnaw to be a toggled pet ability makes life much easier for PvPing with good pet control, and in the odd chance you need a stun in PvE.
A macro to replace the vanilla pet attack button:
I consider that to be the normal state for the pet. Another macro puts him in stun-as-soon-as-you-can state, and wont spend energy on claw:
Just have to be sure to set him back to normal if you want him to put out any kind of DPS. I've got my pet bar arranged in such a way so that the highlights on claw and gnaw are clearly visible as pet state indicator, and it works out pretty well.
These macros aren't needed anymore since 3.0.8. Your ghoul will constantly pool up 70 energy before Clawing so it will always be able to Gnaw on command.
Here are some I use, to save space:Runic Power Dump (Frost)
/cast [mod:ctrl] Death Coil; [mod:alt,target=player] Death Coil; Frost Strike
/cast Rune StrikePet Control
/castsequence reset=300 Raise Dead, Death PactPet Control (Unholy)
/cast [nopet][target=pet, dead] Raise Dead
/cast [pet] Gnaw
/cast [mod:shift,target=focus,exists] Strangulate; StrangulateDeath and Decay
/cast [equipped:Fishing Pole] Fishing; [mod:ctrl] Army of the Dead; Death and DecayIcy Touch
/cast [mod:ctrl] Path of Frost; Icy TouchGeneric FU
#showtooltip [mod:ctrl] Death Strike; Scourge Strike
/cancelaura Hand of Protection
/cast [mod:ctrl] Death Strike; Scourge Strike
/cast Rune StrikePlague Strike
#showtooltip [mod:ctrl] Lichborne; [mod:alt] Death Gate; Plague Strike
/cast [mod:ctrl] Lichborne; [mod:alt] Death Gate; Plague StrikeDeath Grip
/target Power Spark
/cast [mod:ctrl,target=player] Leap; [mod:shift,target=focus,exists] Death Grip; Death GripPestilence
/cast [mod:shift] Blood Boil; Pestilence
/console cameradistancemaxfactor 4