Quick question when you used Loctite 609 , did you use it on the OUTER and INNER races of the bearings?
I used it only on the outer races.
I can see where it also might help on inner races. But on my bike, using a SRAM Force BB30 crankeset, the spindles were snug enough that I have to tap them through the inner races lightly with a mallet to put it together. So maybe it just depends on the snugness of a particular spindle.
I work in a place that does a lot of bonding and loctiting, so I believe the most important thing for those applications is surface preparation. I thoroughly cleaned the BB inner surface and the bearing outer surface with naptha and then alcohol (other solvent would probably work too). Scuffed the surfaces lightly with fine steel wool, then cleaned again. Applied a very light, but thoroughly-covering coating of 609 to both surfaces, with a q-tip, then pressed into place normally. Wear rubber gloves so you don't contaminate any surface you may need to touch. Clean off any excess loctite with a q-tip after installation. Let dry for 24 hrs before installing the crank. that's how I did it anyway.