The main problem with fabric softener sheets is that the volatile oils in them tend to clog the lint screens in dryers, often to the point where neither air nor water will pass through them, which is not good for the dryer.  Whatever clogs the line screen is almost impossible to remove with standard household cleaners. I have filled a gunked up screen with Knight's Spray Nine and had not a drop of it leak through. 

is the liquid stuff half price, too?

Thanks.