MuscleNerd himself identified member of the iPhone Dev-Team has confirmed that the method works, however is a bit complicated, an up to date SAM will make all the pieces easier, whereas on this tutorial we clarify the right way to do it, as you say is a bit messy however it works:
Works on any iPhone and all identified firmwares together with the IOS 5.1, you want to have completed the Jailbreak iPhone in query. right here we clarify the steps it is advisable to follow, even when it appears too difficult, you are able to count on to replace SAM to not be late to reach and make the method a lot easier:-
Here is the method to Unlock Any iPhone Using SAM :-
A. - You must have done the jailbreak on your iPhone
2.-Install SAM from Cydia
You'll find it in the repo repo.bingner.com
3. - Opens SAM find the icon on the SpringBoard
4. - Enter the SIM of another operator
5. - Go to Utilities and select "De-Activate iPhone "
6. - Select "Method" in SAM and choose "By Country and Carrier"
Find your country and company (the original iPhone you have, not what you want to release)
7. - Go to "More Information and copies the IMSI in" SAM Details "
8. - Click "Spoof Real SIM to SAM"
9. - Back to the main screen of SAM and change your method to Manual
10. - Paste the IMSI that you copied earlier into place
11. - Connect your iPhone to iTunes and allows activation
Check that the parameter that appears in iTunes ICCID matches your SIM card, if it does not need to start from scratch.
12. - Disconnect your iPhone and close iTunes
13. - Disable SAM (unchecking "Enabled"), or else completely uninstall
14. - Connect your iPhone again and iTunes will give an error saying that your iPhone can not be activated. It's normal, close iTunes and reopen
15. - You have your jailbroken iPhone, you should see the bars of coverage immediately
16. - If the Push notifications stop working you can fix them using SAM, just enter and click "Clear Push" and then connect to iTunes.
Important: The iPhone is free only for the SIM you put, it is not free for any company, if you want to switch companies to redo the whole process with the SIM you want to use.