Darin,
I have found absolutely NO downside to the sheets. They retain moisture when sprayed well, providing a boost for humidity without them having to be soaked down. When the snake defecates, the urates and feces can be easily dumped into the trash or commode and any liquid is absorbed into the material.
The only thing I do when feeding in the enclosure with a couple of my more aggressive feeders is to push the sheet aside. But generally speaking, I've not had any problems, I just believe in preventative medicine for those snakes that are sometimes more hungry than they are intelligent. <img src="http://www.faunaclassifieds.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt='

'> Moving the sheet is especially important with Burmese pythons as I have read of at least one case of a burm eating a bath towel it had been fed on. It missed rabbit, hit the towel, began to swallow the towel anyway (it had rabbit scent on it) and took 2-3 people to work together to hold the snake's mouth open and pull the towel out. That said, my best friend just got a new burm and set her up on the sheets. She moved the sheets to one side of the cage and fed her on the cleared side with no problems.
As for the washer, the only odor I have found is when you are first washing the sheets. The combination of hot water, bleach, and detergent does little to mask the
initial odor when the cycle first starts. However, the odor fades fairly quickly. I usually allow the cycle to run almost to the point of draining the water and then stop the cycle and put it back to the begining to let the washer agitate the sheets for a longer amount of time before I let it drain and rinse. I occassionally run the sheets through two cycles - the first cycle to clean the sheets - using hot water, bleach and detergent; the second cycle is usually just hot water and detergent to make sure the sheets smell clean and don't have too much of a residual bleach odor (for those time when there are heavier 'deposits'<img src="http://www.faunaclassifieds.com/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt='

'>. With the drought conditions that have hung over my area for most of the past year, I haven't been using the 2 cycle method as often though in order to conserve water. The washer never smells afterwards either way - most likely thanks to the bleach. I have also only done a single normal cycle through when I was short on sheets or time and needed clean sheets NOW and never had any residual odor on the sheets or in the washer. I'm pretty particular about the washer as well (I do not want to wash my clothes and have them smell like snake poop) and my other half has a very sensitive sense of smell and would never go for it either if the odor lingered so I think you'll be safe with your wife. <img src="http://www.faunaclassifieds.com/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt='

'>
Dianne