I was once working in a sporting goods and uniform shop thin which, while transitioning from a DIY belt dryer to a nice new Advance, we were forced to use the flash for some small jobs.
I remember learning to see a steamy vapor at around 30 seconds, and we went ten seconds more. Of course, your results could vary.
Obviously a less than ideal solution, but sometimes, one does what one must.
Very important to try to do this on a table or platformt other than the press' shirt board. The boards were generally not designed for this much continuous heat and could easily warp prematurely.