Devel module and the WSOD on login
This is not a complete solution, but can help.  

If you want to look at something but dont want to spend the time investigating your site's aversion to the devel module, then drupal core's watchdog call can be helpful.  Also, I am assuming you have dblog or weblog module enabled to catch the error messages.  To make it more readable, like a krumo output, I often add my Explain function to a custom module somewhere. Then in the place where I would have used krumo($target); I use watchdog('bug_hunt', explain($target, 5, 'target') ); and go to /admin/reports/dblog and filter for bug_hunt.  That 5 is arbitrary in this case; 4 steps into something can get you target->field_one[und][0][value] = Content.Since I have that function terminating the recursion with html line breaks, it reads well in the log pages.  

I started doing this when I was trying to expound on processes that did not have a page for krumo to inject into (maestro module workflows, etc).  Since then, it has been a reliable fall-back method for me.

The better solution would be to spend the time finding why devel crashes your site, as it might be an issue that will appear again later on.