"Most leeching" is a term used to describe a situation or person that is particularly draining or demanding, often taking more than they give. However, there are several alternative synonyms that can be used to describe this concept. Some recommendations for replacing "most leeching" could include "most demanding," "most draining," "most parasitic," "most exhausting," or "most time-consuming." Other possible options could include "most burdensome," "most vampiric," "most sapping," or "most depleting." Ultimately, the choice of which term to use will depend on the context and tone of the sentence, as well as the specific nuances of the situation being described.