Liquid laundry detergent 

Laundry detergents use different compounds, or surfactants, to remove stains from clothes. Powder detergents use alkylbenzene sulfonate to remove stains, while liquid detergents use alcohol ethoxylates. Liquid detergents use alcohol compounds because they are more stable in liquid form.
To pretreat, make sure to check the care label, and then simply apply detergent directly to the stain, rubbing detergent into the fabric. You can use the cap to measure detergent based on your load size. Pro tip? Toss your detergent cap into the washer drum with your clothes to clean off any detergent residue.
Liquid detergent is better for your washing machine. It does not usually clog your machine and doesn't cause your clothes to stain. In fact, liquid detergent also doesn't fade your clothes. Powder detergents often contain bleach which is damaging to your clothes.