Download the Clear Screen Patch Full mod. Unpack the zip file. Put the ClearScreenPatchFull.fs file in the Chaser/Addons directory. Create the directory if necessary.
Download mod from: http://www.chaser-game.net/?page=downloads&cat=tools
This will only work with the full version of the game, not the demo.Leave a comment if this link stops working and I'll upload it to a free file hosting service.