Re: A better alternative
I believe that it's actually pretty tricky (and expensive) to get something into an orbit which intersects the sun. For a start you have to cancel your orbital speed, which at Earth's distance is a little under 30km/s. For comparison, escape velocity (from the Solar system) from Earth's orbit is just under 17km/s. So it would be easier and cheaper (but arguably less responsible) to send something out into the universe than into the sun. Cheaper than both is to lower the orbit enough for Earth's atmosphere to finish the job.