I pretty much followed the wiki
http://www.mopedarmy.com/wiki/Removing_rust_from_a_gas_tank
except I used the muriatic acid as I bo
ught it from home depot and let it sit overnight. And instead of using the alcohol I just blowdryed the tank and filled it with oil to coat the inside.
Although the Por-15 kit does sound like it would be good if I did it again.