Furthermore, Deva bodies are very subtle and they do not sweat, accumulate dirt and become smelly like our gross bodies. The only time Devas sweat and become smelly are when they are about to die - one of the five major signs of decay. Otherwise they are always clean, radiant and good smelling. The clothes of the Devas are also always clean and pure, and their beauty depends on the merits that they have accumulated when they were humans. Because of this Devas do not need bathrooms as well, since there is no need for them to wash their bodies clean daily. As such, the heavens are places of perpetual purity and cleanness, as opposed to the hells, which are places of extreme impurity and suffering. That's why there's truth to the saying that "cleanliness is next to godliness". The Buddha himself placed great emphasis on hygiene and cleanliness, instructing the monks to bathe and brush their teeth daily. Hair and beard should also be shaved on a regular basis to maintain a neat appearance. He criticized those ascetics who made themselves naked and dirty in order to be holy as being foolish. So there's no question to how the Buddha perceived the merits of cleanliness.
I was reading the "Fruit of Karma" book by Sudassa Onkom sometime ago and came across an interesting anecdote. In the story LP Jaran's disciple Phra Buayao was offered divine food by a certain Deva who admired the progress he has made in meditation. The food looked like ordinary food, but the taste was beyond anything that he could imagine. The amazing thing was Phra Buayao was the only one who could experience it - to other monks it just tasted normal. A small amount of it was enough to satisfy one's hunger. Puzzled, Phra Buayao asked LP Jaran about this and LP explained it to him accordingly, as he too has been offered divine food by this Deva as well. LP mentioned that the food and drink of the Devas are so refined that they are completely absorbed by the body. Ordinary food and drink are only partially absorbed by our bodies and the rest comes out as waste matter. But for Deva food, it produces no waste matter at all. Thus the Devas have no need to urinate or defecate and there are no toilets to be found in the heavenly realms.
Why is this so? Because the Buddha's teaching is about purifying one's mind, and keeping one's body clean has an undeniably positive effect on the mind. Toilets are places where we get rid of the filth and waste matter in our bodies and thus keeping toilets clean is also an act of great merit. I once heard another saying which goes, "If you want to know how civilized a country is, simply look at their toilets." Come to think of it, this is quite true. A good example would be Japan and its generally clean public toilets. This is directly linked to the refined and orderly manner which Japanese people conduct themselves in public. LP Jaran also taught that there's great merit to be gained from building public toilets and keeping toilets clean. He said that if parents want their children to grow up and become successful people, they should instill in them the merits of cleanliness and make them clean the toilet or bathroom regularly. Think about it; there's profound meaning to this teaching. If we can develop it into a habit and apply it to the mind, it will surely lead us to the end of suffering.