again and again dirty throttle flap as well as hose from air filter and engine ventilation

Hello to all Twingo friends. Mine is a bit worried. I hope you can give me a tip. I drive the Twingo from year 2001 as a winter car with many short distances (11 km). I regularly have to remove and clean the hose from the air filter to the throttle flap (every 3-4 weeks). I notice that the car starts badly. There is another hose connected to this hose from the engine ventilation or crankshaft housing ventilation. My questions would be: 1. Why is this now planned, after all, the supply and combustion of the oil residues via the throttle valve into the cylinders. Is this possibly due to the oil or the fuel type ? 2. Would an oil-catch tank be useful here if necessary ? Has anyone ever installed this?