For brick walls, the AC guy just hammered a bunch of little holes with a rotary hammer and put the pipe through, then after he was done he mortared the hole closed leaving a nice seal around the pipes. I imagine a rotary hammer is going to be insufficient with reinforced concrete, a diamond drill is going to be needed.
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.
Typhoon Guitars http://www.typhoonguitars.com