Double spending doesnt work otherwise why dont you go double spend 10btc and show us. It doesnt work anymore the closed that loop.
You are just trying to extort people who have bad intentions with this and then they won't tell anyone because everyone will know they only wanted to use ot for bad intentions. Kinda like buying a stolen item you know is stolen the it gets stolen and you know you can't commit it since it was a crime to begin with.
Double-spending works. It has always worked but not in that sense. You can't double your bitcoins. However, you can send one transaction with a pretty low fee and then send the same inputs with a higher fee, the second transaction will get confirmed and the first one will be dropped from the blockchain. This is all the site does, it's not claiming to double your bitcoins.
Does it still works mate?