Refresh favicon in bookmarks (Firefox)

There is a solution that works on every browser:

• go to www.yourwebsiteurl.com/favicon.ico (works for localhost as well)

• force refresh (Ctrl+F5 for most browsers, or manually)

• restart the browser

In Firefox 56 on Windows I was able to refresh just a specific bookmark favicon as follows:

• Install sqlite-tools from https://www.sqlite.org/download.html
• Quit Firefox (close all open Firefox windows).
• At the command line, change into your profile directory. Mine was at %AppData%\Mozilla\Firefox\Profiles\<profilename>.default.

• Open the favicon.sqlite database using sqlite3:

  sqlite3 favicons.sqlite
  

• Find the favicon(s) you want to remove:

  select * from moz_icons where icon_url like '%search_term_goes_here%';
  

• Delete them:

  delete from moz_icons where icon_url like '%search_term_goes_here%';
  

• Exit.

  .exit
  

• Start Firefox and visit the relevant pages. The favicon will be refreshed when you do this.