I use Assos. I've tried others, but Assos is the only one that I find continues to work for extended periods (without the need to reapply) and that washes out completely. It has witch hazel in it, so it does have a bit of a cooling effect. It did tingle the first few times I used it, but I no longer notice it. This stuff was actually recommended to me by a woman rider precisely because of the witch hazel which has a bit of a bacterial fighting effect.

I basically only need it if I've been off the bike for awhile (so I've lost a bit of my 'toughness' down there) or if I'm doing a ride that is significantly longer than usual. I really prefer it for any ride of 60 miles or longer, no matter how much I've been riding.

It is different for everyone though. I know plenty of women who don't use it all all (men, too). I think, like the saddle, it's a matter of body geometry and personal preference.