How can I get System Information's "Installations" and such to correctly reflect the software I currently have? I installed a bunch of software.

Then I removed most of it. 

I used a variety of methods. AppCleaner for some 
things, 

mdfind -name 'Adobe Flash' |parallel rm -rf {} 


for others. 

I removed app store software in by clicking on the little "x", and then manually cleaned out all the stuff that did not get removed.

I've gone after the receipts and .bom files. 

I enabled locate, in order to get it all.

However, the Installations option in "System Information" continues to display software that is gone. 

I find this disheartening, and confusing.

What strategies do I need to employ to perform the equivalent of say, 

aptitude purge foo


? 

The software is gone. I can reinstall it via App Store or other methods. Where have I missed? Pls advise.
The flat files method of saving receipts was ended in 10.5 Leopard.

For Snow Leopard systems and later, the package receipts are stored in a database at /Library/Packages/db, so you'll want to use pkgutil to query and manipulate the receipts inside the database. It's probably a sqlite store, but the man page and all books I've read strongly recommend using pkgutil

 pkgutil --packages #to list the installed packages


And once you've assembled a list of packaged to delete you can pass them into the tool and instruct it to forget those packages.

 pkgutil --forget com.apple.pkg.HP_Chuckwalla


Reading in the pkgutil man page as well as Peachpit Advanced System Administration book should cover any options I forgot to mention.