After this initial ten day hold has expired, funds that have been on deposit for more than five business days may be withdrawn and additional deposits may be withdrawn after five business days.
And here are the official details from EmigrantDirect:
For security reasons, initial deposits have a 10 business day hold before they can be withdrawn. Future deposits may be withdrawn after five business days.
I did a little experiment to confirm these. In my deposit to ING Direct, I initiated the deposit from ING Direct on Wednesday September 21st. The deposit wasn't available until Thursday September 29th (6 business days).
For EmigrantDirect, I initiated a deposit on Monday October 3rd. It wasn't available until Wednesday October 12th (6 business days). Note, Monday October 10th was Columbus Day.
So deposit availability times for both banks seem close to what's advertised. Refer to this previous post for times it takes to transfer out of these banks, and for more information on EmigrantDirect, refer to this post.