I can't even begin to make sense of that, of course. To begin with, a "dimension" is not a place, it's a measurable extent of some nature, like length, height, breadth, extent of time, etc. So to describe heaven as "a different dimension than the physical world" is in its very essence a meaningless statement. Now, if you said that heaven was a dimension further than the physical world, that would be something else, but then, it would of necessity encompass the physical world and thus retain all its impurities.The realization that heaven is a different dimension then the physical world, and that to gain access to that realm or dimension a human being must cultivate the mind and body. In other words, remove every impurity within our mind and body
Also, given that our bodies are actually comprised of probably more "impurities," and that we would be dead in an instant without them, makes striving to remove them a most unlikely enterprise. A sample male of, let's say 150 pounds would have something like 30 trillion human cells, and at any given time up to 39 trillion bacterial cells, many of which he depends upon for life function. (After a good poop, you may temporarily reduce the ration to 50:50 for a while, but it soon goes back up.)