We have a laundry problem. Allan's shirts get dark greasy looking spots on them. I don't notice them on other clothes but they really show up on his dark cotton twill button up shirts.
I don't use fabric softener or anything other than Tide and I have tried other brands. The spots don't come out with regular stain remover but I discovered a squirt of Dawn direct foam will take them out. Warm water wash and a front loading machine followed by a warm tumble dry is my current routine.