Rather than clearing the user collection, can we use separate cookie jars to make requests as different users? From https://github.com/mikeal/request#examples :
```javascript
var request = request.defaults({jar: false});
var userAJar = request.jar();
var userBJar = request.jar();
request({url: secureUrl, jar: userAJar}, function () {
  // This should work, if user A has access.
});
request({url: secureUrl, jar: userAJar}, function () {
  // This should return a forbidden status code, if user B has no access.
});
```