It never ceases to both amaze and disgust me when they first show up and start to touch the filth, smell it and even get down on their knees and sniff carpets that are caked with poop, piss and lord knows what else lol.
If you expect the unexpected doesn't the unexpected then become the expected?
I love it when Kim smells something and then tells Aggie to "smell this, it smells like a camel's bum!" and then she smells it!. If someone tells me something smells like a camel's bum, I will just take their word for it!
I wouldn't touch my own toilet (which is a LOT cleaner, btw) with bare fingers when cleaning it -- I surely wouldn't touch somone else's poo-infested loo.
They may have good immune systems but I'm betting their stomachs are made of steel. Consider the fact that we can only see the places they are in them with all the lovely little smells that would probably have most of us running for the neartest clean toilet. Not only are they walking around not doubled over but she is actually going in for a closer smell and doesn't get the dry heaves.