While living off-the-grid in our tiny house, we use a complex composting toilet...
Afterwards, we bathe using warm creek water that we heat on our wood stove.
"O foremost of humans beings, one should not pass stool on land that has just been tilled, in bed, in a pasturing ground, in public, in the middle of a road, on the bank of a river or pond, within the water, or in a crematorium."
- Hari Bhakti Vilasa
Third Vilasa, Text 160-161
"There is no necessity of soap. There is no necessity of anything.[...] Early in the morning they cleanse the body. They go to evacuate on the field. After evacuating they come to the river, cleanse the body very nicely, and smear the body with the clay received from the river"
- Srila Prabhupada
Srimad Bhagavatam Lecture
London, September 13, 1969
"Nitya, this is daily affair, taking bath and go early in the morning to evacuate, then wash your hand. Not required, soap. You can take the dirt from the earth and wash your hand nicely, then take your bath and change your cloth, washed cloth, then go to some temple."
Bhagavad Gita Lecture
Honolulu, February 3, 1975
"No soap. Take this Radha-Kunda's... Why soap? You are so devotee of Radha-Kunda, why you require soap? This is nonsense. You take earth from the Radha-Kunda or Vrndavana. Vrndavana-dhuli. Why you require soap?"
Vrndavana, September 5, 1976