Need help with dogs anus...protruding and blackheads

It's been going on for years, like since my dog was 5 all the way to now and she's 11.

I think we were either expressing her anal glands incorrectly, but when we showed our vet they said we were doing it right. Even so, I still just had the anal glands expressed by a vet since then just to be safe.

Still, she's always constantly scooting and her anal is not pretty at all. It's protruding outwards with tons of lumps that resemble almost exactly like blackheads ...yes you and squeeze them out.

To give you an idea, I once spent 2 hours just squeezing them out and still didn't get them all. And the worst part...they just keep coming back.

It's black stuff that comes out and sometimes white....I'm pretty sure it's shit.

I'm worried that if this continues long term, something like an infection, necrosis, or other bad things could happen.

I've seen 3 vets and they all have seen her anus and just shrug it off like it's normal and say basically nothing can be done about it...which I guess I understand.

Is there like a cream or ointment to help?

Or do I have to squeeze out these blackheads from her anus for hours every week only for them to return the next?

A cone will help prevent licking, but won't do anything for her constant scooting.

She's such a beautiful dog, literally every about her is gorgeous I'm not being biased....but her butthole is ugly.

Anyone experience something Similar to this?

Any help or advice is appreciated, thanks