The phrase "most whole hog" can be interpreted as going all out or doing something completely. Antonyms for this phrase would be to hold back or do something partially. Words such as moderate, restrained, limited or conservative can be used to show the opposite of going all in. You could say someone was being cautious, holding back, or not immersing themselves completely if they were not "going whole hog." Antonyms for "most" would be in the realm of least or fewest, indicating a smaller, more conservative approach. Ultimately, the antonyms for "most whole hog" would be conservative or limited in terms of action or approach.