AThe service we are going to use is https://shapeshift.io. it's an instant currency exchange. No accounts are required to convert cryptocoins. So once you have your dirty bitcoins you go to the website. Convert your bitcoins to another altcoin. always go to a smaller altcoin so it's cheaper to convert back to bitcoin (read their fees just so you understand but they're less than tumbling IMO). Then convert whatever currency you chose back to bitcoin. This works because you are going from one block chain to another so it garentee a clean set of coins. I recommend doing the whole process through tor to ensure the best opsec possible Edit: there may be better methods out there I just wanted people to know that they can do it without having to rely on a tumbler
This is not tumbling! There's a complete blockchain trail from your purchase of whatever coin to whatever other coin back to your original purchase! Just because it's not a strictly bitcoin trail doesn't mean it's not still there!
The best you can do is use shapeshift to convert btc to an altcoin that has some kind of inherent security (darkcoin/dash is one and I don't really know any of the others), and then mix them properly, and THEN convert them back to btc.