>>105657978
1. To kill shit dead get yourself a bottle of picrel or any insecticide that has Diazipol, mix five spoons of the product into a liter of water, spray around sinks and toilet and keep the room clear for at least 8 hours.
Check for "domestic use" labels because they generally mean they're way softer, in that case just mix 10 spoons into the same water, since I'm a state-licensed fumigator I get the real stuff.
Cost: around 15 euros.
2. To keep them dead make yourself a roach trap with sugar, water and baking soda.
Cost: 2 euros.