The most efficient format, and the form the Laundries themselves prefer, is a translucent lime-green sphere, 20 or more metres in diameter, made of specialized ufog with the consistency of gelatin. In space, they prefer existing in freefall, with nothing but emself and whatever power-source is connected to it. On planets, or large habs, they prefers to be buried about halfway. Smaller and larger sizes are possible, as well non-spherical forms, such as a tank or bed; but the preferred form has become ubiquitous enough for the 'green sphere' to have become the symbol of medicine in some areas, similar to the red crystal and blue skull used in other regions.
Operation is quite simple: the user simply presses emself into the Laundry, until completely surrounded. Once initially entered, the gelatin moves itself to enter the various orifices, using several techniques to do so without causing any pain or discomfort. In fact, upon entering the lungs, it carries out gas exchange, so the user does not have to work even at breathing.
The gelatin goes to work - again, painlessly - and the user starts being disassembled, starting with the macroscale and working down. That is, first the skin is removed, then the muscles, the bones, the organs, and so forth; depending on the biont, they might "help" peel off the skin, detach pieces, or otherwise play with themselves in ways that would be impossible elsewhere. When sensory organs are removed, the gelatin continues to feed sense input to the brain/mind, to avoid sensory deprivation. Then the organs themselves are reduced to tissues, then the tissues to cells, and so forth, until the user has been reduced to atoms, if that is what is necessary for their treatment.
These Laundries clean not only one's surface, but every single piece of their users. They also do repairs, custom alterations, exchanges, etc; they can also serve as engenerator transmitters or receivers. They respect a principle equivalent to doctor-patient confidentiality, and are neutral healers of all who enter them, repairing damage, healing disease, converting bionts to cyborgs or the reverse, allowing lovers to swap bodies in that version of the marriage ceremony, or whatever else is asked of them and within their capabilities. When provided with Ultimate Chips, if a S0 mind wishes to be moved into a body too small to otherwise carry their mind, such as a chipmunk, they can handle that procedure, as well. For the truly adventurous, there is a 'random/surprise me' option.
Initially there was only one, created by an S2 and provided as a gift to lower toposophics; now, there are many, spread to approximately a million systems, offering their services to all.
When any are asked what er motivation is, the answer given is that e is a pervert, and has found a socially acceptable way to indulge its kink.