What are some strategies for bribing large number of BoDs?

I still have several hundred unfilled BoDs that I did not get around to doing during the artisan festival.  I would like to bribe them up to their maxes as cheaply as possible.

What are some strategies for bribing large number of BoDs?
For example is it better to mass bribe in the morning after server up?

Any NPC is only going to accept 1-6 bribes before they stop, citing "being watched."
 
I don't know how this is determined and six (6) is only my average of experience bribing 1000s of BODs.  Could get more that that from a single NPC.  Just depends upon how often that NPC has already been bribed if at all.

The best strategy is to bribe in the most underused shops.  This typically means in Felucca and the more obscure shops like East Britain, Jhelom, Ocllo, Serpent's Hold, Buc's Den and don't forget New Magincia on the very south end of the Island.

I have found that type, quantity and quality don't affect the cost to bribe as much as how often the NPC has already been bribed.  By finding the most underused NPCs you can bribe even a Valorite 15 exceptional BOD to 20 for free.   You can bribe any BOD for free.  I just used that one as an example of a high-end BOD.

When I show the NPC my BOD and it's a crazy amount in the 1,000s, 10,000s of gp to bribe.  I move on.  I never pay that much to bribe. I bribe most of my BODs for free or almost free.  Be patient.  Don't try to get them all done in one day.  Travel around to get the lowest cost.

I am already trying to bribe every NPC in both Trammel and Felucca. Blacksmith alone requires two runic atlas.

But how long does the NPC remember that is has already been bribed?  An hour, 18 hours, until server up, 24 hours?

Well first, what shard are you on? Hopefully not Atlantic.  If you're on Atlantic, expect to find it hard to find under used NPCs.  I have very little difficulty bribing on the cheap on either Pacific or Siege.

As to how long before you can bribe an NPC again.  I'm not quite sure.  I've tested an hour or two hours and that's very rarely enough time.  I haven't really studied it enough past that to say.

You can tell how about how much an NPC has been bribed by how much they ask you to bribe them.  Obviously if they request zero gold then they haven't been bribed in quite a while.  If for the same BOD an NPC asks for 1000-3000 gp, then they've been bribed several times recently.  If they ask you for 10k, 33k, - 70k, then they have been bribed a lot already.    I'm not sure sure how long it takes for them to get back down to requesting zero gp.  Something to study for sure.  It might be a single server maintenance or it might be a couple of days.  I don't know for sure.

It sure would be nice for a dev to chime in with some info. @Kyronix @Bleak.

I am on Pacific. Where someone else is also bribing a large number of tinker and blacksmith NPCs besides myself.

I play Pacific also, but mostly Siege.  I haven't done any BOD bribing on Pacific though in about one week.