Making smoke
 

hi
I want to produce smoke from an OS46FX using the engine's pressure somone told me its bad for the engine is it true??
If not I have some questions:
1) What oil should i use to produce the smoke
2) how can i build a one way valve and a valve to close and open the oil flow?
3) Where should i connect the oil exit to the muffler? to the close end to the engine? or at the end of the muffler or in the middle? or doesnt it really mater?
Thanks