Uhmm... Not. That gnoll is waiting for me. Pay attention to the text "You return to floor 12 of the dungeon".
I used an Aqua Brew to fill the traps with water, destroy them, then fought the gnoll. (I created these Aqua Brews as a way to deal with fiery enemies, like Fire Elementals).
If I remember correcty and that "bug" is still there, then you can that against the sentry. The sentry doesn’t target you because you are too close to it. It targets you because you are above the tiles. Water does replace them.
The vents in the toxic gas room probably also can be replaced with water, but I’m not sure.
But the main benefit of aqua brews is equipment that interacts with water like ice and lightning effects or armor that lets you walk faster on water or the goo-potion that only heals you on water.
Though I wasn’t aware that it can actually damage fire enemies. First thought this is only about countering burning debuff.
I filled the vents (in the Toxic Gas rooms) with water, and it really worked.
That means Aqua Brews have another use: get free Potions of Purity! I usually save Potions of Purity to deal with the Rotting Fist + another fist combo (especially ones with ranged attack ability). When you enable the Badder Bosses challenge, two fists will appear at the same time).
(I only have the screenshot of the result. Sorry).