It may be worth mentioning and I do not know who else may do or think like this. I try to keep the sides above my must somewhat clean. I figure air is exposed to all the little drops and even fruit bits clinging to the primary inner wall. Usually I only have an inch or two above the top of the must and this is constantly being re-wetted.
If I have a batch that for any reason is sloppy, as my pumpkin wine bubbling, I will halfway thru fermentation take a clean papertowel moisened slightly with a water/sulfite solution and wipe the excess off.
Just food or wine for thought.
People say how fast time flies when you are engaged. Just wait till your married. See how fast it flies then.