If you had six figures in BTC you would have a problem, because it is so volatile. Sure if you have 50k it sucks to lose 10k in a month, but laundering would also cost a lot of money and effort, so it is not worth it. Laundering is worth it when you have a lot of money, but its always risky. I was asking of methods to keep the value while your privacy, not actual laundering (laundering would mean making your government believe the money you have comes from legitimate sources, what I'm talking about is keeping the money hidden).
I was thinking of methods to prevent that. Let me ask your opinion about their anonymacy and security.
You could make unverified accounts in some exchanges, deposit BTC, exchange for fiat and keep it that way until you want to use that money, then you change back to BTC and withdraw. Some exchanges don't require verification for some amounts, so you could make 100 accounts and keep 5k in each one.
Verify accounts in some exchanges with fake IDs and do the same as before.
Borrow them with BTCjam and Bitcoin Lending Club. Totally anonymous, but risky. Also hard to do big amounts.
Buy bank accounts off the darknet and keep the money there.
Buy gold or cash.
What would you say it's the best?
I would keep it in offline (cold) paper wallets, keeping no more than 50 or 100 BTC in each one. Then I'd tumble it slowly, up to $1000 a week. More and more stores are taking btc so I'd spend it there wherever possible.
To get lots of cash? I'd try localbitcoins first, honestly. You might luck out and have a dealer nearby who's looking to anonymously purchase 10s of thousands in bitcoin.
Send some my way, with some background and some incentive I could come up with some pretty detailed cash out schemes, even laundering enough for the IRS (though you do lose some to the government) to think it's clean.