Wash Ass (ウォッシュ・アス) is a chojin styled after a toilet basin.
A Peruvian wrestler modelled after a super toilet. After his teacher Benkiman had been defeated by Kinnikuman, Wash Ass faced Mantaro Kinniku in the 2nd match of block "B" in the Chojin Olympics: The Resurrection. Wash Ass repeated his teacher's tactics and flushed Kinniku Mantaro down the body of his toilet. Kinniku Mantaro - in turn - repeated his father's tactics and clogged the toilet with his trousers. After this, Wash Ass was defeated by Kinniku Mantaro. He was defeated within 19 minutes and 29 seconds. He has abbreviations for TOTO on his chest and water closet on his belt. In the 4Kids Ultimate Muscle dub, he is a movie producer (which befits his dub name).
Wash Ass appears during a grand ceremony for his match against Mantaro Kinniku.  The crowd celebrate his arrival by throwing plastic faeces at him, while he carries with him a photograph of Benkiman.  He reveals that Benkiman asked him to avenge his defeat at the hands of Kinnikuman by defeating his son, Mantaro.  It is at this point he proceeds to drug an attractive woman with his Temptation Smell, while forcing her to make physical contact with him until she is forcibly made to achieve peaks of pleasure and collapse. 
The match between Mantaro Kinniku and Wash Ass begins with a series of blows exchanged.  Mantaro is swallowed whole by Wash Ass, but manages to clog his drains with a pair of trousers, and this backs-up Wash Ass and temporarily incapacitates him.  He soon removes the pants with his Pressure Arm, before he uses his Temptation Smell once more to lure Mantaro to sit upon him.  Mr Sasaki helps Mantaro to snap out of his stupor by overpowering the scent with that of his favourite food. 
Mantaro proceeds to tie ropes around Wash Ass, to prevent him releasing his Temptation Small, but he uses his Wash Ass Shower to break the toilet lid and free himself.  Mantaro breaks the 'shower nozzle', sending a spray of blood into the air, and continues to break the toilet bowl and graphically defecate inside the bowl itself.  This act clogs the toilet, at which point Mantaro uses his Muscle Millennium to defeat Wash Ass at 19 minutes and 29 seconds. 
- A drug emitted through an alluring scent, which can entire a person to do any deed that Wash Ass desires
Wash Ass Shower
- A bidet that shoot out to skewer his victims with a spray of water powerful enough to tear holes in metal
- Turns arm into a plunger to remove obstacles that get trapped within his internal plumbing
Stool Cover Off & Open
Hell's Toilet Flush
- Submitted by: Masanori Nakanowatari (中野渡正宣) of Aomori