Jumbo App is easiest! IIRC twitter's API doesn't allow you to bulk delete tweets from the outside. I've found that exporting all tweets, getting the IDs, and t

Jumbo App is easiest! IIRC twitter's API doesn't allow you to bulk delete tweets from the outside. I've found that exporting all tweets, getting the IDs, and then deleting them in the browser using the twitter.com only browser API will allow you to delete tens of thousands of tweets with no rate limits. I did something similar here: https://github.com/kylehotchkiss/fakeblock https://github.com/kylehotchkiss/fakeblock but it's not documented well and Twitter's export file format actually tends to change on a somewhat regular basis.