I would go for an inheritace setup to do this - particle based, not vertex based 😉
First step, prepare your fluid using a fluidPBD - that´s vital as we need groups.
As I said - create an emitter for the fluid, 2 groups and use first one only.
Check how many particles are in the fluid ( HUD) .
Now create another emitter that covers your object with same amount of particles as a shot on the surface area ( you might use volume or grid as well , but difficult to do exact match for number of particles though not impossible )
Next step, use an inheritance mod in time mode to be completed within x frames and restrict that to second group of fluid emitter and inherit the object covering emitter.
Now at a given time when everyone has noticed this is a fluid, do a group change restricted by field/falloff and key the offset value for the field to grow from 0 to 100 and take particles out of the fluid by this and make them available for inheritance this way....
If you would keep them in fluid simulation, they are not able to inherit properly !
fluid to object.c4d