: I am house sitting at the moment so i require a quick fix is there any chemicals i can pour down my toilet to stop the bathtub filling up.1. Uses less paper!!!!! If the tank is accesible with a minimum of effort, try lifting the lid…..if may be possible that the tank itself has failed you can try a drain cleaner…..and if nothing else works call a vacuum truck and have the tank cleaned…if you talk nice, the may give a whirl at removing the clog