The word "more feculent" expresses an increase in the level of dirt or contamination. However, there are several antonyms that describe a decrease in dirt or contamination. These antonyms include words such as "clean," "purified," "sterile," "hygienic," "disinfected," and "sanitized." These words denote an absence of dirt or germs and suggest a state of cleanliness or purity. Using these antonyms can be useful in situations where you want to convey the opposite of "more feculent," such as when discussing cleaning procedures, hygiene standards, or the state of a living space.