No. 3 - Acquire a Twisted Bow
Do not wait to attempt the Inferno until you get a Twisted Bow. I can’t speak from experience since I haven’t done it, but while I’m sure that PvM experience in Chambers of Xeric can help in the Inferno, it is not worth the hours upon hours of extra time you would spend just hoping to get the weapon.
And it’s certainly not worth the two billion coins you can alternatively spend to acquire one, even if it is the top Ranged weapon in the game.
It’s much more manageable – and cost efficient – to do the Song of the Elves quest and get a Bow of Faerdhinen (BowFa). And yes, you should corrupt it, not just because it looks cool, but to avoid degradation.
While the price of assembling a BowFa is going up (like pretty much everything in the game these days), it is still far cheaper than a Twisted Bow, and it is more than capable of doing the job, specifically against TzKal-Zuk.
Most importantly, it has the same attack range as the Twisted Bow, which is crucial when it comes to the corner safe spots against both Zuk – and the Jad that is spawned when Zuk dips below 480 life points.
And while most may recommend using a Toxic Blowpipe during the waves (which is 100% feasible), corrupting your BowFa is just as efficient and obviously doesn’t use ammunition. And again, it gives you more flexibility with a better attack range.
Blowpipe also isn’t an option against Zuk except against the Ranger and the Healers (where it’s pretty much a must). I recommend spending time learning the Blowpipe walk ("Woox walk") in the basement of the Wizards’ Guild in Yanille, and use a Runelite metronome. Even with no prior experience, you can have it down pat in 20 or 30 minutes.
Don’t worry if you need to spawn an extra Ranger/Mager set just because the BowFa has a slightly lower damage output than the Twisted Bow.
Yes, you can have unfortunate rolls with the Ranger hits, and without manually off-ticking the set and prayer switching, those can unfortunately sink your run. But with this method, I’ve done it with as many as five set spawns before. Your goal is to get an Infernal Cape, not to beat the all-time speedrun record.