Jim it took me a few hours although I did it across 3 sessions throughout the day. If I delete a friend then I am no longer showing on their friends list either, hence you wont see me on yours. I know nothing about the technicalities of computers but below is a post from a WGTLS user on this very subject;
"Unfortunately your WGT friends list is tied to the game window. I wished they'd remove that function; once you're playing who cares what's happening with friends not in the actual game you're playing?
Every time the status of one of those 50 or 100 or ??? friends changes it puts a digital pulse into the game window, and if that happens whilst your meter is in action ... bad news, baby. To a lesser extent, so does chat in the game window - if you have chatty partners or opponents, try turning the game chat off (just click on CHAT in the upper left scoreboard section) while you're making your swing - once you're done click on CHAT again to to observe all those 'nice shot' comments you've just gathered."
Now maybe my results with the meter are purely coincidental but it does seem strange that I should get such a good run on it today. If the experiment works, fantastic. If not I can always make friends again with those I deleted.