Have you gone Kynetic?
Kynetic Aviation Smoke Oil is a low viscosity, amber colored petroleum base oil that is non-toxic and specially formulated to produce a brilliant white smoke trail with incredible hang time in scale engines and turbines. It is made from highly refined base stocks and contains no additives that can harm smoke systems. Its low viscosity and ability to produce billowing white smoke clouds that are reluctant to dissipate make it the perfect choice for professionals looking to impress a crowd. It features a non-flammable formulation which causes it to be an extremely safe and superior alternative to dangerously ignitable home-made oil and fuel mixtures.
Material Safety Data Sheet available upon request.