As you know you can still increase Garwals happiness with the Mend Pet glyph.
Well, presuming this also works, Garwal will be uber;
1) On your level "Garwals level + 10" hunter, eg: Garwal 66, you 76; Tame Garwal.
2) Go to a stable, put as many damage buffs ESPECIALLY Beastial Wrath on him as you can, and Mend Pet too.
3) Put him in the stable.
4) Repeat till your stable is full.
5) Level up once, and take him out the stable.
If this old glitch still works, he should have all the buffs you gave him for 7 days. And you should also have a full stable of Garwals to do it with
Reply if this is still working, if any hunters can test it. My hunter is only level 70