Hello,
I am an experienced professional with good experience in code cleaning.
Regulary have to use these tools for improving page loading performance.
For css, I mainly use Css lint and for other purposes and dirty markup basically.
But there are also other tools including the webdeveloper tools in chrome that I regularly use.
And w3c has some online tools too.
Let me know if you are interested.
Thanka,
Manoj Baruah