Tattle-Tale Grey
AKA "dingy" laundry is caused by incomplete soil removal and or soils being redeposited on laundry. Both are caused by either using too little detergent and or incomplete rinsing.
Using too little detergent or "soap" for laundry means half the battle is not won, that is soils removed from laundry cannot remain in suspension and rinsed away. This leads to soils ending up back onto textile fibers.
Remember laundry detergents and soaps perform several functions: one is to remove soils and stains from laundry, the other is to keep said materials in suspension to be flushed away during rinsing. Soaps and detergents also contain ingredients to soften hard water and deal with minerals found in all water. If these minerals including those found in soiled laundry are not kept suspeneded, they also will end up back on laundry.
Fels Naptha soap was so successful because unlike all soaps, which are merely fats, oils and alkaline substances (lye), Fels added petrol (naptha) which as a hydrocarbon, deals with oils by dissloving them very easily, in essence a solvent. This meant women didn't have to do all that rubbing, boiling, scrubbing, since the petrol did the hard work of laundry. Indeed period laundry guides advised laundresses, housewives, etc, not to boil laundry when using naptha type soaps; warm, hot and in the case of Fels and perhaps Kirkman's Borax worked very well in cold water.
Because these soaps also contained builders (washing soda, etc) they washed laundry better and eaiser than simple lye and fat based soaps. They also kept the soils away which resulted in brighter laundry.
Modern detergents use complex chemical cocktails with surfactants and enzymes, to deal with soil removal and suspension. Phosphates were the first choice, but as they are banned in many areas we have all and sundry sorts. Still the same rules apply, if not enough detergent is used, and or rinsing is incomplete, the result will be dingy laundry.
Depending upon where your friend lives, he may have hard or at least mineral laden water, thus his laundry may have a build up of detergent residue and soils.
Best remedy is to "strip" laundry by washing in the hottest water possible using a good water softener and NO detergent. White King, Calgon, or if he can find it, STPP. Add about 1/2 cup to 1 cup (depending upon load size and type of washer), and see if suds start appearing in laundry. If water is the area is very hard, add same amount of packaged water softener to the first rinse, then keep rinsing laundry until all traces of suds are gone. It helps to use warm water for at least the first and perhaps second rinses.
Soft water,especially water softened with phosphates causes detergent, soap and other residue to leave textiles and if one likes, become "detergent" again. This is why one does not add any more detergent or soap. In addition trapped minerals in textiles will also come out and be flushed away.
