I never have a need to "tumble" my coins, as I do not vend and have not bought any products on Silk Road. But if I did need to store my Bitcoin I would use a paper wallet which is offline storage so I know my coins are secure. Then, if I wanted to get them back online and send them to Silk Road I would import the private key into Bitcoin-QT and then send them to BitcoinFog and then tumble them into Silk Road.