The word "most purifying" implies a process that cleanses or purges impurities. The antonyms for this phrase would encompass words that convey uncleanliness or an abundance of impurities. Words such as "contaminated," "filthy," "tainted," "polluted," or "corrupt" would be antonyms to most purifying. These words suggest a process of accumulation or deposit of harmful substances or elements. Antonyms of most purifying could also be linked to less noble notions like greed, dishonesty, or dishonesties epithets like "venal," "unscrupulous," "disingenuous," or "corruptible." Overall, antonyms of most purifying would encompass anything that goes against the idea of cleansing, rehabilitating, or renewing.