When I was a child (living in an Asia), we had a separate toilet and a bidet (side by side). The awkward part was moving between the two. Even with that separation, accidents can happen (i.e. feces in the bidet). I wonder if the single Japanese toilet is superior to two separate seats (toilet + bidet) in regards to hygiene.
Oh man I feel your pain. My family had one of those here in Brazil and I hated when this happened. Anyway I do not live in the house I was raised anymore and now every modern apartment in Brazil only have a toilet, this is sad for me.
Having said that, The plastic cover housing of the sprayer itself might get soiled in cases of extreme explosion (i.e after mexican lunches etc haha) in which case I had to use some TP to clean the mess up.
I found this bidet (mentioned above) the easiest to use.
- Easy to install (5 - 10 min)
- Small footprint (doesnt include the cover so a lot cheaper) and fits most of the commodes
- Pretty much no touch mechanism - turn knob and you are done ( drying with TP optional)
Regarding the sprayer, the question is not necessarily what happens to it when it's not spraying water... when the nozzle is in the process of spraying you, it's unavoidable that some of the contaminated splatter goes back into the nozzle.
Anyone who uses that toilet will inevitably share the germ cultures from one another's feces. That doesn't strike me as very sanitary.
You ever spray a hose away from you and get hit with the splatter? Imagine spraying the hose up to clean the underside of a gutter. Can you imagine getting hit with splatter? Can you imagine the hose getting hit with splatter? Can you imagine the rim of the nozzle getting hit with splatter?
Sure, the outside of the nozzle/arm will get by splatter, just like the rest of the toilet bowl. But the nozzle rim and interior will remain splatter free because of the jet of water. Any surface where particles can touch the stream will be washed clean by the stream.
This is no different to the splashback that can occur when poop hits the bowl water (water that's been touching the splattered sides of the bowl).
It's no grosser than a regular toilet, and your butt will be cleaner.
Meaning that cross-person fecal contamination should probably not be one of your major concerns. The nozzle does some sort of intense rinsing. I don't know about sterilization.
Good, that would help with my fear. But then again, what's the algorithm of their cleaning. How does it know for sure it's clean? Honestly us Americans can be messy. I can only image what it would be like using one of these at Walmart, a public rest stop or even your infamous Gas Station restroom (if you want to even call those restrooms).
My wife dragged me to an appliance shop in the Mission (SF) and they had a toilet like this in their bathroom. At first I was shocked and appalled at how forceful the stream of water was - especially as I had it on the 'low' setting. Then I became aware of how long it was spraying because after 30 seconds I had to turn it off. With the combination of these two (and the heated dryer), I didn't have any problems.
Most of the ones I used had two settings for temp and two settings for power of stream. A few of them had an angle setting as well. You just press and held a button until you felt clean, then used toilet paper to dry off.
I thought about your last question the moment I tried these washlets. It just seems (to me) physically impossible to design a mechanism to prevent that from happening.
* How does the toilet know that everything is clean? With toilet paper, you can just wipe with new toilet paper until there is no more residue.
* What is the algorithm for the toilet's spraying? Does it end up spreading diluted feces around, or is it careful to spray outward-in?
* What happens if feces end up on the nozzle? Is there some kind of auto-cleaning mechanism? Otherwise it might end up spraying old feces back to me.