take control over particles

I have a buoyancy script that applies forces to rigid-bodies so they seem to float in water. I have a leaf particle system that I was hoping to use to spawn leaves that land on the water and then float. I see that I can get collision events when the leaves hit the water colluder, but I'm not seeing a way to take control over a particle and apply forces to it. Also, it doesn't seem obvious that I have enough information available to just replace a particle with a similar game object.

I'll probably just try to build the leafs as game objects and not use particles unless someone could suggest a better option?

Thanks.