I've asked about repeating the nightfall in a previous question, but now I want to know if repeating the nightfall will add to my Bad Juju bounty. Each nightfall counts as 3 strikes I believe, so re-running the nightfall might be a quicker option if it counts towards the bounty more than once a week!
Does repeating the nightfall and weekly heroic strike count towards the Bad Juju bounty?
Yes, repeating Nightfalls strikes should give you 3 every time. Just a heads up, the weekly heroic (even at the lowest level setting) gives you 2 every time. This guy did 13 weekly heroics. Given that the weekly heroic has matchmaking now and is more forgiving, you may be better off doing weekly heroics if you don't have a group.
However, I would only recommend doing this method when there is an element burn, as the nightfall/heroics are much slower than a normal strike without them (Read: I wouldn't bother trying to do 8 nightfalls or 12 heroics this week on one of the longer strikes [Cerberus Vae III / Valus Ta'aurc]).
The fastest method is probably to find 2 others and do the Nexus Strike at level 14 over and over. It can be done in about ~5-7 minutes a run, with a good group. If you get a Nexus nightfall/heroic with a burn that'd probably be the fastest way.