I started to use a chorreador in MV in 1995 in a house that I was staying in below Stella's house... no one told me that I should empty the grounds after each usage. I figured the mold was mostly killed by the hot water. The coffee got a lot better once I started emptying it out after each use. The filter was nearly full when I got the house and so I was mimicking whoever was there before - must've been 500g of coffee in there. It's good to laugh at oneself!