bleach is actually better to run thru drains then Drano. It is safer then Drano b/c if you don't rinse the draino out well enough it will eat thru your drains and bleach won't.
My bathroom drain was clogged around Christmas time and I finally ended up using bleach and bought a new kind of plunger
http://www99.shopping.com/xGS-master...4~r-1~CLT-INTR and when I plunged it I heard it pop thru.
You can also buy a gun like think at Lowe's for about $30 that you pump air thru the drain. I bought both and I think the plunger is what worked in combination with the bleach.
Run a cup of bleach thru all your drains every once in awhile to keep it clear.
When I cleared mine after Christmas I called my dad singing "I did it - I did it!"


http://www.yourinspection.com/Drains.htm