I provide a ;‘laundry pack’ in a ziplock bag. Our laundry facilities are shared so in the bag I leave one sachet of Tide (or whatever is cheapest when I shop - sometimes a couple of pods) and eight quarters (enough for one wash and one dry). I also let the guests know that we have an outdoor washing line (which is at the back of the building so they aren’t aware of it) and that if they need pegs to ask me.
Each laundry pack usually just stays in the apartments for months. Hardly anyone does laundry.
I read somewhere that dryer sheets are the work of the devil environmentally-speaking so if guests want them, they buy their own.