Can people who have made applications talk about these. Where did you do it (country) how long did it take, can you send it in before the denial if you know you will need one.

You cannot file a waiver/hardship letter until the visa is denied at the consulate interview and they have confirmed that the beneficiary is eligible to submit the waiver. Timing depends 100% on the country you file in. You can find more information on specific country timing from the consulate website (sometimes) or from other filers on www.immigrate2us.net in the 601 or 212 forum.