since we switched to JT's mega-steam http://www.megasteam.com/ our layout is cleaner, track comes clean faster and our scenery does not have a residue on it.
and we still have great smoke production.
plus the layouts outside our room have stopped complaining about a smoke cloud drifting over their layout. (smoke dissipates faster)
running 6 days a week 6 or more hours a day this is a big deal.