When i was a bit younger,i used to dry my underwears in my bedroom because of privacy, my mother always told me that they should be dried outside where their is sunlight and freshair.Hanging your underwears indoors is definitely not a healthy way.
Underwears trap sweat and vaginal discharges throughout the day.
First let’s start with the best material for an underwear.Cotton is the best material because it absorbs vaginal discharge and extra moisture.Synthetic materials like nylon don’t allow the vaginal area to breath hence trap heat and moisture which could lead to yeast infection.
Most people wash underwears after having a bath.I think this is not the best method because they are not properly washed with clean water, If you have enough underwears its best to wash them once.
Underwears should be cleaned with warm water which will aid in killing bacteria like E.coli often found in underwears because of fecal contamination.3% hydrogen peroxide could be added on the water to help in removing sweat and stains(optional).Recommended amount of detergent should be used because too much can leave a slick residue on top of the germent which could lead to irritation.
For blood stained underwear put a pitch of salt and rub then run it under cold water.Salt pulls out the blood while cold water loosens it from the fabric.
After washing the underwears its best to hang them in open spaces or under sunlight.It decreases the chances of bacterial growth which could cause ringworm infection, Urinary tract infection and pubic skin diseases.
Good hygiene better health 