A swashplate leveling tool, or the allen wrench idea, is worth its weight in gold.
The last few times I used one to level my swash at low, half and full stick I didn't need any trim for the heli to fly perfectly.
And I'm still running that way, with zero trim on cyclic.

This is the tool I use:[link=http://www.readyheli.com/T_Rex_Swashplate_Leveler_p/leveler.htm]Trueblood Engineering[/link]

And the bench users guide within that page is the absolute best, most clear and concise, description of what needs to be done to get a perfect swashplate setup.

I highly recommend reading it even if you don't intend on getting the tool.