I also have taken scrap fabric, and even old terry-cloth towel and put it on top of the steam a seam I wanted gone, re-iron the area, and just keep moving the scrap fabric until it is gone...I haven't had to do it on a large area, so not sure how it will work, tho...
Since Dunster got that from their site, that is probably the best thing.
Good luck, and please know I for one have "goofed" plenty of times...
Kif