Among the suggestions lowering giant plastic pillows to the seafloor and filling them with oil, dropping a huge block of concrete to squeeze off the flow and using magnetic clamps to attach pipes that would siphon off the leaking oil.Some have also suggested conventional explosives, claiming that oil prospectors on land have used such blasts to put out fires and seal boreholes. But oil engineers say that dynamite or other conventional explosives risk destroying the wellhead so that the flow could never be plugged from the top.Along with the kibbitzers, the government has also brought in experts from around the world — including scores of scientists from the Los Alamos National Laboratory and other government labs — to assist in the effort to cap the well.