Is it really true there are really 24/7toilet slaves eating mistress' shit and drink her urine? don't you think that the toilet slaves are gonna die of the shit which is undeniably poisonous? how to make the life span of any toilet slave longer?

Yes, there are. It can be unhealthy if one doesn't keep aware of the risks and do something to counteract them. Continual use of a variety of broad-spectrum antibiotics is an important thing, as is staying extra-hydrated, as the kidneys will be working overtime.