Forum Moderators: Robert Charlton & goodroi
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /([^/]*/)*index\.(html?Šphp)\ HTTP/
RewriteRule ^(([^/]*/)*)index\.(html?Šphp)$ [www\.example\.com...] [R=301,L]
Your measure of success is for the "/" URL to return to the main index within a few months.
The named files will likely remain as Supplemental URLs for a year. They will not be classed as duplicate content. You cannot remove them. Just enjoy the fact that for some searches your site will return two results in the SERPs, increasing the chance that someone visits your site.
I am aware of a site where "/" (normal result) ranks at #1 and "/index.html" (supplemental) ranks at #5.