This extension removes entries from the new Downloads history, either after finishing a download or when Firefox is closing. By default, downloads will be removed five seconds after finishing.
Please note that this add-on is set to remove only new download entries by default, so your existing history will not be removed. An on-demand option is available.
If you experience any issues, such as downloads remaining in the history, please contact me.
I personally recommend using this add-on in conjunction with the new Download Status Bar Add-on!
I have created a “successor” using Web Extensions: Download Cleaner Lite. It has a reduced feature set, it supports only timed and on-demand removal. This new version is compatible with Firefox Quantum (57+).
Important: Development of this add-on has stopped. Use it at your own peril.