If you are using straight enamels, strong consideration should be given to a mineral spirits thinner. You can get a can at Home Depot/Lowe's for 2-3 dollars.
The mineral spirits cleans just as thoroughly, is significantly less toxic, is not as flammable as lacquer thinner, and because it primarily contains petroleum hydrocarbons (also called petroleum distillates), it provides more of a lubricant base for your airbrush components. Of course, you can also use it to thin your enamels. The Model Master thinner is very good, but is considered somewhat "hotter" (higher volatility). You might find that your paint goes on more evenly and with better consistency with mineral spirits--or maybe not. Try it.
Gip Winecoff