Numbers 19, The water of cleansing

I randomly came across this chapter in Numbers today and decided to actually look a little further into it.  I'd love any other comments.  In order to make sense of my post though you'll have to read the chapter.  http://www.biblegateway.com/passage/?search=Numbers+19&version=NIV

After reading it I wanted to know if God used the ashes to actually cleanse the Israelites.  I still can't quite put it together in my head but this is what I came up with.  In Chapter 17:13 the people complain that they can't go near the tabernacle, this is God's way of making them clean enough to come as close as they need too.  It doesn't actually cleanse them, it's seems to be more of a ceremony.  This is what I'd love more knowledge about.  My commentary doesn't explain this in language I understand.

This passage also has a deeper meaning which I found in Hebrews.  One example is chapter 9:13-14, "...the ashes of a heifer sprinkled on those who are ceremonially unclean sanctify them so that they are outwardly clean.  How much more, then, will the blood of Christ...cleanse our consciences from acts that lead to death..."  I wonder if God put this in the Bible just so that His people could use it as an example later on.  Probably, God does everything on purpose. 

If they weren't cleansed this way after touching or being near a dead body then they were cut off.  If we had not been cleansed by Christ's blood than we would be cut off...