I thought I'd share with you how I was able to clean my drains (and just about anything else in my house) for super cheap and without the use of toxic chemicals :)
Pour a little bit of vinegar down the drain (to loosen up the gunk). The pour baking soda around the edges of the drain. Pour about a cup of vinegar down the drain and stand back b/c it's going to fizzle. After it's done fizzling repeat if it needs and use the salt for extra scrubbing power.
My drains came clean and hopefully so will yours :)
You can also use baking soda and vinegar to clean the tub, counter tops and just about anything else you need it for.