Every five days he washes (there is not enough water to do it more) and holding up the cloth in the bath he squeezes the water over his now tired limbs and tries to get the worst of the desert out from underneath his fingernails. He thinks that the desert, like it once did to the planet and like the war did to Anakin, is slowly creeping into him whether he wants it to or not. He thinks that he now knows why Anakin hated the sand.
He said that it got everywhere. He said it was gritty and course.
But still Anakin would cope better then he does in these circumstances as he knew the sound of the desert.
Lying back in the shallow bath and watching the blue plastic roof ripple above his head, he wonders what has become of that shattered man he left in the burning shores of Mustafar. He knows that whatever has is something dark and twisted, and he thinks that if that is the case, it is like the dark and twisted body that he left burning. Even the ash surrounding him was burning. He tries (unsuccessfully it seems) to not think about such things as it only depresses him and makes the already broken man inside him break just a little more.
He wonders what happened to that selfless boy Qui Gon found on this desolate planet.