The toilet bowl stuff is available at Dollar Tree stores.
I asked them how much for the cleaner,
$1.00
The name of the stuff is "The Works"
Here is a link to their website:
http://www.theworkscleans.com/toilet.htm
And if you feel adventurous, try this:
http://www.43things.com/things/view/1004741
Active ingredients: Hydrocloric Acid 20% Rodine 50.1%,Perfumes .1%