Oh the irony, I just had a complete (finally!) clean-out of my shared bedroom with my younger sibling. I share two rooms, one with my younger sibling and then another separate room with my elder sibling and the problem is, they both are never tidy, not ever. Unfortunately for my younger sibling, I stay in that room most of the time and I am a person who likes a clean space all the time and typically, my sibling happens to be the complete opposite. I normally am picking up at least a small amount of rubbish in the room and taking it downstairs to the bin and having a small amount of cleaning in that way at least once a day. But still the room tends to get cluttered with my messy sibling always making his mark of rubbish and eventually, I start to feel uncomfortable in the room and end up with a mass clean-up which takes at least a day to complete. This though, sometimes could take longer depending on how slow I am working.
As I said earlier I have two rooms but I don't have as much cleaning responsibility in my elder siblings room as really, I am never in there, I don't even make a speck of dust in there and elder sibling at least attempts to keep it as clean as possible. Although just recently we're cleaning it out and putting new furniture in and such so it's a bit of a mess that I have to cope with. But when I was in there we spilt the rooms into halves and I had the cleanest room all the time in the household and in that room because at that time, I clean my room at least 2-4 times a week.