Should a person dump that out or use it for starter on the next batch? I've read both.

I believe Skeeter pee recipe calls for a yeast slurry from a previous wine batch

you can do either

if it was a good batch keep it , if it was not what you wanted don't

you can also use it to make Vinegar

that is a traditional use of the mash

I'm a newbie to this. I made the first gallon with frozen grape juice concentrate with water and 4 cups of sugar. It's still fermenting after 13 days. I made another gallon with Welchs grape juice in a jug and used 1 cup of sugar. It finished after 9 days and I believe it's 11% alcohol by volume.

When I rack my carboys,,I siphon from the top down so as not to get the settlement.I don't keep it.I throw it out.The alcohol has already "eaten" up most of the good yeast.Why keep it?

I usually thro it all out or put in the bear bait.

Are drunk bears easier or harder to hit?

I'm with upstate. I throw it out. New batch new yeast

Drink the sludge-it will cure your hangover.
Better if you mix it with a little hot pickle pepper juice.

Bottle it and mark it "Friends and Relatives" It will help cut down on the amount of wine you give away.

I threw it out. Didn't look very appetizing to me. The wine does have some punch to it. Then this morning I opened the fridge and a bottle fell out and broke on the floor.