If it's brand new you don't need base cleaner. Base cleaner is for removing snow impurities from the snow guns, sap, dirt, diesel and oil from snowcats or sleds etc. It makes the wax absorb better by removing these particles which could displace the wax.
Otherwise, use a citrus cleaner like Chief Firewater or something made by Toko, Swix or Dakine. I'd avoid using gasoline, kerosene or other alkane hydrocarbons because this stuff can displace wax in the base as alkanes are paraffin. It's the same stuff you are trying to clean off the base, doesn't make much sense to clean with it.