Power Siphon for magic finding

I was wondering if power siphon always gets the culling strike in a party, even if the dps is very low. I assume if the blue animation over the slain monster activates, it means the skill got it's culling strike, but I've been told otherwise before.

However, if another skill is better for making sure your iir/iiq benefits the items found (better aoe skills), i'd like to hear about it.
Thanks

PS will always cull. It works alright for mf culling. I would rather use an auto hit spell like arc. Arc-cull-iiq-iir would be fine for a 4l culling skill. You could also use the mf culling polex to free up a link. With PS you kinda want to link GMP and chain to hit more mobs and you also have to worry about accuracy if not RT.