Ok so long story short: It was fantastic but I think no other review really explains how this goes because I thought I was literally stepping inside on someone's house and that is not exactly correct.
The thing is that when you arrive, Diego -who is super kind- would explain you the house rules and give you the keys so you don't have to depend on him. The house is like a corridor where you have access to the bathroom, kitchen and your independent bedroom so it is really less invasive or awkward than what I was thinking.
If you're traveling on a dime this place is great: the bed is super cozzy, you can wash your clothes, you are right behind an underground station but if you prefer to walk, little Venice is close enough to walk on a good morning.