My questions are:
When does the timer start in this challenge?
Should I go for Decanter or Concoction on Handmaiden for it, as I’m trying it solo?
What is the meaning of life?
EDIT:
Thanks all for your input, managed to do it. Now on to Enchanter’s Lair challenges… Oh mommy…
42?
EDIT: Sorry, could not resist. But I concur with the question 
Found this. I assume decanter is what you need and conc pots. I assume the person inthe video probably used No Escape and Impatience talents.
Timer start right after you open the first cage.
Decanter is usually a better option (though I did this one as Battle Wizard, not as Handmaiden) for these challenges.
There’s none.