Prevent Internet Explorer from caching SSL client certificates

The thread Clear SSL State using vbscript contains this command :

"C:\Windows\system32\rundll32.exe" "C:\Windows\system32\WININET.dll",DispatchAPICall 3

The thread how to clear authentication cache on ie7 with Javascript? advices to paste into the address bar :

javascript:void(document.execCommand('ClearAuthenticationCache'));

Install both certificates, select the one that you use mostly the next time you visit the site, and than use "InPrivate Browsing" (CTRL+SHIFT+P, or via menu) whenever you need to use the other one.

InPrivate browsing is like if you would have clear all cache, history and start with a brand new/(unused before) browser.