It depends on the game and the context.
Yes, I have, for highly structured things like "Meet your Covenant/Clan people!" especially on smallish games (or small clan/covs). Or interest groups. In a larger context (a whole sphere or giant ass plot scene) it's been hit or miss. I tend to clam up/freeze up in large scenes, but what they are valuable for to me is to take note of others who I'm interested in and would like to tag for later. I have even paged folks with "Hey, I tend to feel a little frazzled in large scenes, but your PC would have caught the eye of mine when you talked about liking to knit doilies/your latest research/you love roller derby/I saw that you too are from city/country/timeperiod, would you like to RP in a smaller setting sometime?"
I tend to look at wikis /after/ I play with people rather than before, but I think it's because wiki still feels new-ish to me. I also look at the wanted boards and sometimes even if I'm not their wanted type of PC if it looks like it'd dovetail well with mine or someone I know, I will reach out to people about RP based on that too. (Or hook them in to PCs I know also love the things they love, even if I don't).
I think ultimately what tends to get me the most new RP connections is personal outreach. It's a lot of asks though. So I go in cycles where I need to take a break from it because you wouldn't think it would be hard but it sort of is on a personal level (even though the reception is almost always positive).