I don't think you understand what carpet bombing, actually is.
For best results you need a squadron of BUFFs and a <deleted>-ton of ordnance, mostly dumb bombs to keep the cost down. Then you drop them all over a fairly large area instead of trying to hit one specific target.
AFAIK Israel doesn't have any bombers, let alone a squadron of Stratofortresses. That, and I doubt they'd have any allies left if they did that in Gaza.