Ooooh, that feels all wrong.
Seems to me .htaccess would block visitors that you may want. And while Google may obey the directive, they may also misinterpret a referrer-specific directive as cloaking.
If you want to get the same effect, here's what I'd do:
- Change the page to which the offending links point. Have it say "This page is gone, but you can get the information you want here" and make that a link to a new page.
- Set up your server to return a 410 code when folks visit that page.
- Set up a new page with the old page's content, so folks can click from the old to the new, but visiting bots and browsers get a 410 code and dump the page.
That will get Google to de-index the page in a hurry.
Another option: Simply add noindex, nofollow to the targeted page.
But I like the 410 option, because that should break the authority flow and has the best chance of giving Google what it wants, short of removing the link.