Hi hon , I found this on someone else post hope it helps ...
steam for zaby
how to set up steam in zaby
create a prop (i used blue fish as i don't have them anywhere else) and rotate to lay on side
place in tub just above water
Under script click advanced, then attach emitter
Texture file : cum.png
Particle life: 14
Emitter life: 14
Particles per sec: 1
Speed: 0.00
Start scale: 0.81
End Scale: 5.38
% life fading in: 3
% life fading out: 3
Alpha scale: 0.10
Spawn cube x: 50
Spawn cube y: 50
Spawn cube z: 50
Normal x: 0.1
Normal y: 1.0
Normal z: 0.0
state invisible
Place it exactly where you want it, and save n release!