I am very interested to see someone else to give this a shot. I always seem to be refining this, so I'll post some new files soon I think.
As for my experience, soaking in IPA is OK, but doesn't clean out all the nooks and crannies. It'll clean the surfaces ok, and if you agitate it's really the best way to get the bulk of the excess off quickly.
I've tried ultrasonics with limited success. It didn't seem to clean out the holes like I thought it would. I still resorted to IPA and air hose spray.
Working with the atomizer the past couple of weeks has been pretty good actually. Once I hooked up the foot switch and plumbed a dedicated IPA bottle it really has become my preferred method. I can adjust the air flow with my foot and quickly switch between air only and atomized IPA. The atomized IPA is actually very gentle on the parts and I can focus the stream in all the right places. Deep pockets and holes clean out quickly now.
I do want to have the ability to go from a super fine mist to a much heavier IPA flow. I am going to try to add a flow control valve and open up the IPA orifice to see if that works. I'll let you know.