[Plugin: Almost All Categories Widget] completely remove plugin from database

i installed almost categories at one point and had to move to a custom solution for my needs.

after un-installing, it remains in my widgets list no matter what i do.

how can i remove all instances of this plugin from my database?

is there a prefix that i can search to identify it in the database?

thanks.

http://wordpress.org/extend/plugins/almost-all-categories/