Holga Flash "Sync"

I have been experimenting (with my other gear) with rear curtain flash sync, and I really like the trailing effects it creates. I would like to try some flash shots with my Holga in Bulb mode, and I was wondering if the second flash that the Holga shutter generates takes place before the shutter is closed or after. I know the trigger mechanism is very simple, so would it be possible to modify it so that it fires as the shutter is released? This would give the option of utilizing both or either flashes. (by covering the flash with a black card or a hat)

Cheers,

OK... I just answered my own question.

With about 30 seconds experimentation, I discovered that my Holga, (120N) sends two signals to the flash shoe in Normal shutter mode... but only one in Bulb mode. I think it has something to do with the mechanism cycling the shutter past the aperture in Normal mode, and holding it in place in Bulb. That is too bad, but I don't think there is not a whole lot that can be done about it. There are workarounds, like hand-triggering the flash, but it might be more hassle than it's worth. I'll think about this for a few days and see what I can come up with.

Cheers,