Hi, I always just chuck my bras and tights into the washing machine with everything else. Yes, I am lazy and yes, this does lead to tights being snagged and bra hooks bending. So I am going to change my ways...if I do a delicates wash, with just my underwear, do I put it in a bag? If so, do I need a special washing bag, or will a pillow case do? What's the point of the bag? Enlighten me!! Thanks!