Aggression Introductions are not going well!

[SquigglyPigs]

I have a 3.5 year old female pig, Bean who lost her friend several weeks ago. I adopted another female that is the same age, Apple, and introductions are not going great.
I did a 2 weeks quarantine of Apple and introduced them in neutral territory. There was lots of chasing, rumblestrutting, and chattering from Apple. Bean was terrified and just tried to avoid her and stay still. When Bean would run away from Apple, Apple would chase and tear out hair. Then she bit Bean and I separated them.
Next, I put their cages next to each other for a week so they could interact with bars between them. They did great and I found them laying next to each other and trying to groom each other between the bars. After a week of this, I did another intro in a neutral area.
The second into went okay, but lots of the same chasing and rumblestrutting but no full-on fights. I deep cleaned the cage (which is 2x5) and put them inside together. It went back to square one with lots of chasing and fighting. Bean tried to stay still in a corner but Apple would come find her and chase her out, biting at her as she ran away.
Bean now has one bite, lots of hair pulled out, and some slightly bleeding scratches from Apple’s teeth. I have them separated again.
What can I do to help bond them? Or is this just a personality difference they won’t get over? Apple has lived in a group of about 10 female pigs at the rescue she came from so I can’t figure out why she can’t get along with Bean, who is just minding her own business. Any tips would be much appreciated.

 

[bpatters]

How long are you leaving them in the neutral area?

Are you cleanig EVERYTHING in the cage so that nothing smells anything at all like either pig?

Do all the hideys have two doors?

 

[SquigglyPigs]

They were in the neutral area for 4 hours today.
I thoroughly cleaned the entire cage with 50/50 vinegar and water solution. They didn’t have any hideys - just fabric draped over areas. I had step stools as hideys at the beginning but they were still getting trapped with multiple entrances so I quickly removed them.

 

[bpatters]

Did you wash all the fabric and all the hideys? Water bottles? Food dishes?

Have you taken all the hideys out and draped fleece strategically across the cage to break up the lines of sight? It definitely helps if they can't always see each other.

I'd also leave them in the neutral area longer. I had one group I left there about eight hours before I put them in the cage.

 

[SquigglyPigs]

Okay thanks. Yes I did clean absolutely everything and had the fleece draped in a way that it seemed like a hidey across the area. It’s hard to find a time to do it for 8 hours because I have to supervise constantly because the bites happen so fast. I’ll try to find a time this week.