If however, an item such as a crayon or lipstick escapes the check, the dryer drum may be stained. These drum stains must be cleaned before they stain other garments. This should be done by using a spray cleaner, a laundry pretreat product, or a mildly abrasive cleanser. After the drum, has been cleaned, one should tumble a load of wet old rags, or towels on regular temperature for at least 20 minutes. There still may be visible signs of the stains on the drum, but they will not transfer color to future loads.
Fabric softeners can be a source of unknown stains.
If a fabric softener is poured directly on an item, it may leave a stain. The stains will vary in color depending on the softener used, or it may be a gray color if it has attracted soil from the laundry. These stains are easy to remove. Simply dampen the area, rub it with a bar of soap and relaunder the item. Mild alkaline products such as toothpaste, perspiration, and facial soaps, or acidic products including deodorants, and hair sprays, are often to blame for unknown stains.