Sure, but why stop at imagining? I think it would be worthwhile to actually carry the liquid. Otherwise, I can see a person with illusions about their "centeredness" (or whatever) imagining their imaginary liquid being perfectly still. A real liquid won't conform to your imagination; it will only answer the laws of physics.
In my early martial training, I got a 4 foot rope with a 10 pound weight attached to the end. The other end of the rope was attached inside a 6 inch long PVC pipe. That was my handle. I would twirl the weight around me using my ankles, knees, and waist. Minimum use of shoulders and arms.
I kept my center stable as the forces pulled me in all directions.