yea, i would never ever EVER freaking dare "clamping" a screw with my HANDS?! are you guys insane. that is so dangerous its not even funny. what if your hand slips?? where do you think that dremel is going to go??? right into your balls..
always, and i mean ALWAYS clamp it into a sturdy device thats connected to the floor, not you. like a kitchen table, or your counter top, or better yet, a vice. just get a cheap C clamp or get one of those fancy German clamps. or even a simple spring clamp. don't use pliers, if might work one day, but sooner or later your just going to get tired with your other hand and slip away, right into your body.
this is not a "helpful" piece of advice that you should just 'keep' in mind. this is something you should take care of right now.
its worser than doing a suicide run with out your heatsink on.... boom.