Thirsty Hippo has sachet form too but if it is a Thirsty Hippo the logo and design is very obvious. THippo sachet uses sponge within the package, so unless you poke and squeeze, it will unlikely to leak. But yes one can spill the liquid when the container falls over.
Putting the issue with Thirsty Hippo aside, I have previous used another brand with similar refillable dry agent (pour away the liquid and put a new bag in it). Once I spilled some while on kitchen tile while removing and it is gluey and extremely alkaline. In fact my skin in contact cracked and flakes after 1 day.