You want to use something that will kill the mold or it will just come back... Try this first
https://www.walmart.com/ip/Mold-Armo...waAo8wEALw_wcB
And then if it still needs further cleaning if you have a hand held carpet steamer you can use it or Tuff Stuff which you can buy in auto part stores works well too.
It’s important if you’re winter storing and having your boat wrapped that they put plenty of vents in the wrap and I would also suggest several containers of Damp Rid.
