I live on my own so it's easier and cheaper for me to hand wash small items of clothing and underwear, rather than use a laundry or a washing machine. I always use Ecover Delicate washing liquid, which is produced without animal testing and is kind to the environment.
The washing liquid comes in a recyclable and refillable plastic bottle. It is a clear pale thick liquid, with no distinctive smell.
Ecover Delicate is designed for washing fine fabrics and wool. I find it is mild enough for hand washing any fabric as it contains plant based ingredients which are kind to the skin, and has no petrochemical ingredients.
I think this washing liquid works well in warm water or hot water, it does not have to be very hot. It turns into a pleasant lather and seems to remove dirt or light staining effectively. I have never left garments to soak in a solution of this liquid and I think it would be advisable to check the washing instructions on the garment label before trying this. You can safely add a neat drop directly onto a stain before washing.
This washing liquid can be used in a washing machine on a delicate cycle.