On my website, I have a long list of 301 redirects I'm sure that some of them could be removed by now, as some of them have been there for several years, but I wouldn't like to guarantee there aren't any sites out there linking to the old URLs.

But none the more for that occasionally I want to reuse/revive old URLs that had previously been redirected. Yet removing them from the .htaccess file doesn't cancel the redirect. I've got redirects that I tried to remove three months ago that are still active. They aren't listed in .htaccess but they're still happening. And it isn't a browser cache issue because I've tried them on browsers and computers that I've never used before.

Any suggestions would be welcome, because I'm stumped!