If you are not living on it, and the smell doesn't permeate and stay, why does it matter what it smells like?
Personally, I have a difficult time believing that there are enough volatiles with anti-mold properties, and the ability to escape an aqueous solution, to provide real anti-mold relief. I suspect the fan moving air about does more in this regard than the solution.
If you really want to prevent mold, kill mold that is already there, and have the boat cleaner in this regard than when you put it away, paraformaldehyde is what you want. It is sold in many hardware stores, or on-line. One brand is SunPac: https://www.doitbest.com/products/600025
It sublimes, so goes around the boat as a gas. You don't want to be inside the boat, and when you return it needs to be opened up and aired out for 20 minutes or so, but you won't have mold.
We use these whenever we need to leave the boat shut up in the tropics. Pure f'ing magic, and the only thing that works there - people who are afraid of "chemicals" use tea tree oil only to find they are cleaning mold when they return.
Of course, winter in Philly is not summer in the jungle when it comes to mold, so many weaker things could work well there.