Reading through this thread, as a VP/Executive Officer of Regulatory Compliance and Operations for one of the largest banks in the world made me cringe... so, let's cover a few things, simply for clarification:
1. Cashier's checks generally can be verified, and usually carry a number on them to verify the check.
2. Cashier's checks, while not easily forgeable, can be forged. However, it is generally noticeable. For example, some major banks require a wet signature on a Cashier's check; fraud checks generally are photocopied. Chase, however, does use a pre-printed signature, so it isn't always the case.
3. Wire transfers are generally the easiest for transactions like this, but they do come with fees.
4. 99.9% of banks require advance notice for withdrawals over $5,000. In the day of debit cards and bill-pay, cash is not something kept in large quantities at banks these days.
5. Withdrawing, or depositing, $10,000 or more is not a huge deal as people seem to make it out to be. It's very, very, VERY common in the banking industry, and it simply is sent for review. Almost all of the time, the IRS does not give two shits about your large deposit. So calm down.
6. Whoever suggested depositing $9k increments at a time... yeah, no; do not do that. That is 'structuring,' and THAT is far worse than any CTR. Structuring is generally used by money launderers, and banks have many, many systems that will detect any possibility of the activity, and flag your account and alert FinCEN (Financial Crimes Enforcement Network) faster than you could say "I want to make a deposit."
So yeah... there's the run down of answers to the thread.