Something Tells Me...
...That these will coat a dryer's drum and filter even worse than regular dryer sheets, which are already pretty ruinous. When I got my pair of centre-dial 'Tags, one of the major problems I had to tackle was a horrible grey coating inside the dryer drum and the inside of the dryer door, from years of dryer sheets. It took very hard work to get the coating - and the sicky-sweet smell - off of everything.
Dryer-sheet residue had even built up on the filter, making its nylon mesh hard and brittle. That caused the filter to develop a big hole in it, which the dryer had blown - you guessed it - a couple of dryer sheets through, sending them into the dryer's ductwork, just a'waitin' to cause a fire. Fortunately, I discovered all this in time, and it was easy enough to correct.
Did I mention I hate dryer sheets? ;-)
P.S.: What really puzzled me about all this was that the washer (an LA 108) has Maytag's simple, reliable, foolproof softener dispenser built into the agitator, making it not only possible, but easy, to use liquid softener, which is cheaper than dryer sheets. I don't understand some people...