"Again, it is my opinion but, all those "smoke effects" mess up the weathering and thus are pretty much useless, to me anyway. Besides, on a nice warm/hot day, the real steam vapor exiting from the whistle usually can't be seen anyway." . . . . . Hot Water
I am fascinated by these ideas. As a matter of fact I have not seen these before and, I believe, they add to our discussion.
1) Now, with regard to achieving prototypical accuracy we will not want to allow what normally happens to a prototypical locomotive (i.e. the effect of water vapor, steam, etc. ) to change its appearance so we should not be interested in whistle steam. How whistle steam might impact weathering on a loco is not clear. My weathering is painted or I use Bragdon powders. I imagine the lamp oil being changed to vapor could impact the weathering, but that in and of itself, is prototypical. I don't think my weathering would be affected. In all my years of using smoke fluid, I have seen no change in the paint on the loco even when I spill it.
2) On a warm day we normally do not see the steam vapor from a locomotive whistle. True. The fascinating thing is, we could operate our models on a cold day so we could see the whistle steam. Wouldn't that make using whistle steam fun?
It seems to me that even when logical voices make sound arguments for three rail whistle steam models, there are still some who try to portray them as non prototypical on a two rail OGR Forum board. To make it even more interesting, some of these folks are three rail "Hi Railers" who try to make these same arguments. The logic in this is escaping me.
Uh oh, just saw another post suggesting I am "not the smartest tack in the drawer" because I sit there and suck up smoke. Well, Mister, I smoke cigars, too and I am really smart. So there. By the way, I installed an exhaust fan in my train room, so I am exhausted.