I remember asking once, we don't we just shoot our surplus trash off into the sun and was told that by the cost of launching it outweighs the benefits. Fair!
But what about all of the old satellites and space stations? Why don't we just send a giant magnet around the earth once or twice and then slingshot all that space junk into the sun and thus giving all science fiction writers (when they return from their strike) a plot point they can no longer use in their film scripts?
Seriously though, without the cost of breaching the atmosphere, this seems really cheap to pull, why don't we do this? Why isn't this a standard thing?
That's not how orbits work. You can't just point at the sun, accelerate slowly for 10 seconds and then you will arrive in a few hundred years. If you did that, you would still orbit the sun, just in a slightly different orbit than before. To actually reach it or get near enough to it that the junk burns off, you have to expend a lot of energy.