This is a interesting question. This is how I reasoned it out.
I think there are three situations here (assuming rotationally invariant):
The object is very deep where it cannot overcome the electrostatic force from all the positive charge above it, with only its Buoyant force.
The object is close enough to surface to where the buoyant force and the electrostatic repulsion has a net upward force and it accelerates up to the surface.
There is a sweet spot where the downward electrostatic repulsion exactly cancels the upward buoyant force.
Assuming each particle of the fluid has a net positive charge, then the direction of the electrostatic repulsive force is dependent on the amount of liquid above and below the object. In this case (1) there is so much fluid above it (and hence positive charge) than below it the ball will actually sink!
If the ball is close to the surface than there will be more positive charge below it and hence contribute to the net upward force (buoyant and electrostatic repulsion) and thus accelerate (non-linearly) to the surface and perhaps float above the surface (if $mg<F_{electrostatic}$)
If there so happens to be enough liquid (and charge) above the ball so that it perfectly cancels the buoyant force it will stay suspended at that level. However, this equilibrium is unstable for any perturbation would cause it gain a net forc down or upward and accelerate.
Remember I assumed that it was perfectly in the center of the pool or glass of bucket.