"Carpet" bombing is nothing more than concentrating a high density of bombs in a restricted area. It was designed to take out troop or supply concentrations, and used relatively small bombs (100-500 lb) to ensure the bomber could carry enough to cover a large area.
Most of the ones I have read up on in Korea seem to use only 9-12 B-29s per mission, and they were generally targeted at staging areas and not cities. Most of the missions against cities appear to be "precision" bombing missions against factories, marshalling yards, bridges, etc.
Dams were off limits until mid 1952 when they were hit by combined Navy and USAF strikes to take them all the way out. Skyraiders were noted making torpedo runs on the floodgates whereas the USAF went for the power generation stations. These were touchy as they didn't want to cut off power to much of China and the USSR Far East to cause a widening of the war.
Even now the missions flown over Afghanistan are not like the ARCLIGHT missions from Viet Nam which used three B-52s, each armed with up to 108 x 500 lb bombs, and which would clean out three square kilometers of jungle. This war sees only single bomber raids on front line positions.