Cookies won't reset on iteration in JMeter 'Loop Controller'?

Question

Using Jmeter 2.12, what could cause the cookies to fail to reset during a JMeter Loop Controller? I've tried everything I can think of, but each time through the loop, one of the cookies from a previous login still remains. It doesn't seem to actually clear the cookies.

Here is how I put together my loop:

Thread Group 1
  -- Loop Controller (3x)
    -- Simple Controller
      -- HTTP Header Manager
      -- HTTP Cookie Manger (with 'Clear cookies each iteration?' enabled)
      -- BeanShell sampler - with code that tries to clear all cookies
      -- HTTP /login (gets cookies and auth headers)
      -- ... various HTTP Samplers ...
      -- HTTP /logout

I tried adding a Beanshell sampler with this code (as shown above) but it doesn't seem to do anything:

import org.apache.jmeter.protocol.http.control.CookieManager;
import org.apache.jmeter.protocol.http.control.HeaderManager;

CookieManager cManager = sampler.getCookieManager();
cManager.clear();
HeaderManager hManager = sampler.getHeaderManager();
hManager.clear();

Answer 1

Ok, I figured out the problem. Even though the 'HTTP Cookie Manager' has an option called 'Clear cookies each iteration', the 'iteration' it speaks of does not include a Loop Controller. What it refers to is the 'Thread Group' iterations/loops only. This was not clear and I wasted half a day until I figured this out. Wouldn't have been confusing if the checkbox said 'Clear cookies each Thread Group iteration' instead. Very disappointing.