[vbresults]

If you don't want an email at all, change the second line to:

PHP Code:

$userdata->set('email', null, false, false); 


I think that should work, and it is the cleanest way to do it: the email field will be blank.

I highly doubt there is a hook as expansive and low-level as you describe. If you do anything very different than what was suggested, things will get complicated and not be even close to "clean". Nonetheless, if you decide to go another route, good luck friend.