Myself and many friends have been using dehydrators for years w/minimum of problems and a maximum of satisfaction. As long as you keep the temperature from getting too high, they work wonders for speed-drying paint, glue, and putty. As for trusting the finish, I have never, ever seen anything bad happen to paint anytime after it comes out of the dehydrator. The only problems I've ever seen were a few bodies that warped because the inner temperature was too hot. That can be easily adjusted if you get more airflow into the dehydrator.
Alternatives to store-bought include the box/lamp idea above, putting the body inside the oven w/only the oven light providing heat. Dehydrators work by accelerating curing rates by 1/2 for every 10 degrees farenheight over ambient the dehydrator is. If you already live in a hot/dry climate you really won't need it. They're also great to warm parts and paints before spraying...if it's cold where you spray, at least having the paint and body warm while you spray and a warm place for it to dry makes a huge difference.