Sacred water in trial of Sekhema--POE 2

So the trial of Sekhema... You're supposed to be able to replenish your honor by spending sacred water you pick up during the trial "rooms".

Can anyone tell me WHERE to spend the water? Even walkthroughs online etc don't say HOW/WHERE to spend it. I'm assuming I am missing something very simple?

I do the challenges, get to the end... nowhere to spend it, do the next one, nowhere to spend after, etc. SO by the time I get to the last boss encounter, I am at half honor with all this water saved up and no way to spend it to get my honor back up before the big bad at the end.

Would appreciate any help!

There are certain rooms where you can select shrines that replenish your honor, but you have to pick the correct path to reach these rooms. Rooms can only be reached by certain rooms before it, not by every room in the previous level. So you have to choose your way through the trials carefully.

Thank you so much!

The water can also be spent at the end of the trial run for keys based on the total amount sunk. I haven't totaled this at all but I had 300+ left over, turned them in and got a single bronze key.

EDIT: And will sell relics as well.