HOWDY Mike welcome to wine making talk.
In a food canning line, treating the food long enough to achieve nine log cycles of kill is considered sterile. For reference simple washing stainless equipment in cold tap water will remove five log cycles of bacteria. Hot water adds another and soap in the water a second (ie 7/9 of the way to commercial sterility) For the micro lab tools are sterile if they have been retorted for 45 minutes at 121C/ 15 psig live steam. Another method for loops is to heat them in a Bunsen burner till red.
For me,, first an foremost the tool must be clean, ,,, free of obvious mechanical dirt. This can be done in wine or a fluid like milk with a spray hose. A second requirement is that the tool should not be wood or other porous material. . . . . I will rinse siphon tubes and bottles with K meta sanitzer, but don't see the point on tools for punching down the cap.
The must is already a mix with some bacterial contamination. I think of it as “a multi component food preservation system”. Over 10% alcohol does wonders, pH knocks out many bacterial families, free SO2 is a barrier, anaerobic conditions / CO2 prevents most organisms, fast growth of selected yeast , ,,, and I guess I consider these more important to the wine