I wash mostly at 30, sometimes 20, as its the cheapest for a full load. but I do add laundry detergent to everything, to kill the germs.
I also clean the washing machine with special product and setting, every 2-3 months.
there is only me. I don't like the idea of very hot washing, must be expensive to heat the water that high, also as I am washing just for me it is uneconomical to wait to have enough for different loads. so I tend to put everything in together.
the person who washes knickers at 60, do they have elastic, doesn't that temp wither elastic.
anyway each to his/her own. I don't use any cloths for wiping anything in the kitchen, unless I throw it straight away. never have. don't like the idea. ditto handkerchiefs.
for surfaces I use paper towels or anti-bacterial wipes and discard. the environment won't make me change now. too old. and too young to have ever used cloths, washable.
except, I have gone back to a face only flannel, as i think it helps exfoliate, and is rather a nice feeling, and when in a hurry does for a quick dab when rushing.
don't have a shower. bath takes more time and energy than I have sometimes. never use the flannel in the bath. put my head under the taps so always wash hair at same time.
I wash the flannel at 30 with everything else, but put disinfectant in wash.