WOW THE ZYBEZ GUIDE SUCKS.
Summon a tortoise when you bank. Recharge your summoning as soon as you summon it so you don't need a summon pot for bunyip.
Inventory (Including tortoise, so 46 spots):
24 Brews
12 Super restores
Range pots if you want... but the brews kill the bonuses. So I don't recommend it.
1 Bunyip pouch. (Equivalent of 27 sharks, 1 shrimp, and a cabbage

(544 hitpoints))
2 spaces for enchanted bolts for boss, and addy bolts for aviansie.
1 mith grapple (Duh)
2 spaces for Trollheim teleport runes (Duh)
1 emergency teleport (VITAL)
The tortoise should hold half of the brews and restores (12 brews and 6 restores), while your inventory keeps everything else.
You have 3 spots left after banking. Put in some cheap food, although I prefer to just use sharks for the heck of it. 3 more spaces will be freed up by the time you get into Armadyl's Eyrie (Runes and grapple). Addy bar drops and the clue scroll will take 2 of those spots, and if you are lucky you might get some swordfish (Yes! Extra hp).
Solo like you would normally do, keeping Kree'era out of melee range with the minions. When you drank all the potions (By then your tortoise should be close to expiring), click "Get BoB items" and you have yourself back all the potions. Summon bunyip after dismissing the tortoise. (DO AFTER THE KILL, don't dismiss/summon when boss is out).
You will find yourself drinking the brews a lot less. Kree'era sometimes drops a range pot, and I pot up after brewing to max hp. Ruby/dragonfire first to take advantage of the brief boost.