Batthub residue is a term used to describe the dirt, soap SCUM, and other debris that can accumulate in bathtubs over time. The two most common solutions for removing this residue are 'RING' and 'SCUM'. RING is a chemical cleaner that is used to dissolve the dirt and soap SCUM, while SCUM is a type of scrubbing brush that is used to physically remove the residue. Both of these solutions are effective at removing bathtub residue and can help keep your bathtub clean and hygienic.