One thing that is a bit of a blessing about "odor control" is that Jahi's body is on a ventilator. The breathing circuit is "closed"-- meaning, both the inhalation and exhalation takes place inside of hoses that are not open to room air. The lung secretions are likely to be a dominant source of bad odors at this point, very icky and infected smelling. The circuit on her trach will somewhat contain these odors.
When someone on a ventilator has a breathing tube inserted thru the mouth, or as a tracheostomy, the suction catheters can be contained within this closed circuit, with a type of sterile plastic sleeve over the catheter. This is usually the method used in a hospital situation. This way suctioning can occur without disconnecting the circuit every time, thereby the patient has decreased exposure to infection, as well as the staff having less contact with secretions.
There are also suction catheters which require the circuit to be removed from the trach every time, and a clean or sterile catheter is used. A lot of people with long term home ventilator care situations don't need to practice "strict" sterile technique, but instead use "clean" technique.
For those interested, here are some pics of suction catheters, and a guide to "home care" suctioning of pediatric trachs. The procedure is pretty much the same for kids as well as adults. There are some risks with suctioning-- and prolonged or inappropriate deep suctioning can cause low oxygen conditions, as well as serious and abrupt slowing of the heart rate, with abnormal rhythms. Jahi's body can't cough up or mobilize secretions, so she would have to have deep suctioning to get the gunk out. She also can't cough or react to suctioning, so while she may have heart slowing or oxygen issues, it wouldn't cause her distress. Long term scarring of her lungs from deep suctioning probably isn't much of a concern, since she is deceased, and we are waiting for her heart to finish.
http://www.tracheostomy.com/care/suction.htm
http://www.bing.com/images/search?q...ach&qpvt=suction+catheter+for+trach&FORM=IGRE
Her PEG probably isn't all that smelly, unless the insertion site has infection. AFAIK, she has no major sources of open infection, like deep bedsores, or infected surgical wounds. Her mouth has no "breath" going in and out, so it may be somewhat smelly if you are close enough, and her mouth is open. (We have a saying in anesthesia that "bad breath is better than no breath at all".)
We can all imagine the types of odors produced "down below". Many of the odors of the bedbound can be controlled with scrupulous hygiene of the body, prompt changing and replacing of soiled linens, prompt removal of medical equipment containing secretions and body fluids, and odor masking things like scented body lotion, air fresheners, etc. This is a great deal of work, by the way, and requires very dedicated caregivers.
In my experience, comatose patients do have a type of "sickness" odor emanating from the skin itself, but if you are motivated enough, you can manage (but not eliminate) all of the odors associated with a comatose, bedbound patient. It is a lot of work, though. (IMO!)