Does anything ever resist Purulent Ooze in Gaol?
Henwen
Mboze
Arebati
Ngai (lands fine on it with aura up but good luck getting it into that state solo)
For Arebati just Undax3 Rayke is enough to land Ooze.
For Mboze sometimes it will be enough but if you want to be 100% sure you need to do Undax3 Rayke AND either water SC (so you can MB ooze on it) or land Frazzle 3.
Either of those two will make Ooze 100% landing, in addition to just 3x Unda Rayke which sometimes is not enough.
Never had that issue on Arebati.
I'm not sure for Henwen, pretty confident the Mboze method I described will work, but probably even just Rayke.
Personally I farmed my points on Henwen solo using MNK, or PUP? I forgot, one of the two, I think I tried both and settled for MNK.
I was using several trusts and usually I managed to do enough damage to 5% before I died.
Had a couple of failures here and there but not too many.
Speaking of other T3s, I don't know if Ooze lands on Ongo v25, but you can easily solo >5% on SCH.
Likewise I've got no clue on Xevioso V25 and, of course, it lands perfectly fine on Kalunga V25, just BST solo, the same as Bumba V25.