MindenMan has the anser if you want to remove most of the fusels...
I come from more of a distilling background and Activated charcoal should remove most of the fusels. But unfortunately not methanol, not that its a hazard worry, just more of a foul taste and hangover worry... Just remember that using this method will strip most of the Apple flavor but will leave you with a much cleaner drink, so your Apple Jack wont be much of a Apple Jack anymore.
So if your worried more about the fusels than the apple flavor then Activated charcoal is the way to go.
Here's more on using Activated charcoal for purification from Wikipedia...
...alcoholic beverage purification
"Activated carbon filters (AC filters) can be used to filter vodka and whiskey of organic impurities which can affect color, taste, and odor. Passing an organically impure vodka through an activated carbon filter at the proper flow rate will result in vodka with an identical alcohol content and significantly increased organic purity, as judged by odor and taste."
- Wikipedia
And from homedistiller . org:
"The carbon works by being a type of "molecular seive", trapping the molecules which are larger than ethanol. They become trapped in the pores inside the carbon, and also by surface energies on the carbon. So it won't remove methanol, but only larger molecules (eg the fusels). Likewise, the trapped molecules are sometimes held fairly loosely to it, so if you try to filter too fast, they can be washed off the carbon and back into your spirits.
Make sure that you always pass your polished spirit through a paper filter. Many of the impurities are held by very fine carbon dust - and will still affect the flavor. If you pass even crystal clear polished spirit through a paper filter, you will notice that it becomes grey or black. You'll notice the cleaner flavor too. It doesn't take much - just a little bit of tissue paper or cotton wool in the bottom of a filter, and you'll trap that loaded dust.
Soaking neutral alcohol with activated carbon for a week (or even months) will help remove some of the off-flavors - this is known as "polishing" the spirit.
The spirit should be diluted to 30-50% before polishing."
homedistiller . org
But most importantly...
Don't polish spirits that you want to keep the flavor of (eg whisky or schnapps).
homedistiller . org
So that said, if you leave it in activated carbon for more than a few days, it will strip most of the Apple flavor, but you will end up with a cleaner drink. Soak it for a few months and you will have something that tastes much more like a vodka and have a much cleaner drink...