Yes, it will balance it out to around a 50/50 level depending on the amount added and the original strength.
I've been using some 0 Nic, unflavored to reduce some of my 6's down to 3's but only the liquids with the strong throat hit even at 6. It's pg though. I mix it half and half, shake it really well and let it sit for about a week before I use it. So far, it's worked well and I haven't noticed a reduction in flavor at all.