would you mind going into details as to why and how it's harmful to the strings?

i tried that once when i was really experimental (it's not rock it's just weird)
here it is this is really terrible: Sky Cadet on MySpace Music - Free Streaming MP3s, Pictures & Music Downloads

"Hold This For Me" it's most obvious
"A Glad Spider" also has it, but it's mostly dominated by a pedaled piece,

both songs will give you a headache, because all the stems were recorded separate to each other

I don't think it could be much worse than using a whammy bar, I mean all you're doing is stretching the strings, right? It may make it out of tune, but you could always tune it and put new strings on.

Why sure. He said he was playing his guitar with a screwdriver, weaving and plucking the strings with it. Most screwdrivers I know of are made up of metal that is thicker than your normal pick or what else is used to play a guitar. Since strings can hold only so much pressure a screwdriver would wear down the strings rather quickly.

I'm not trying to offend you mr dave if I did haha
I was just answering the question with an answer.

no worries, just that you're the only person to specify that it would be bad for the guitar strings. i think we just interpret the use of the screwdriver differently. i'm thinking of it more like a slide that goes between or below the strings. guess it really depends on the particulars of the OPs playing style.