Anyone know a thing or two about African Greys?

I'm at my wit's end with one of mine. He's in his terrible teens and we've had him for about 10 years.

We have another girl, very good girl, for about two years now.

My boy is very destructive, and that's fine because he hasn't destroyed anything we can't fix yet. They're never out without supervision.

My boy likes to fly to the curtain rails and picks the curtains off. That's fine. He likes to nibble the tops of our curtains. He likes to sit on the couch. He's got a perch on top of his cage, and we've got jungle gym/ tree for them too.

The biggest problem I have with him is that he flies to my girls cage. A LOT. She doesn't like him. I chase him off all the time. She will tolerate him in his cage if he's snuck in there (sometimes he'll take a walk to her cage and I don't hear him). He just likes to sit in her perches (same perches he has).

He knows he's doing something wrong because the moment he hears or sees me get up, he flies back to his own cage.

The problem is he will do this in excess of 30 times a day. I have them out their cages for about seven / eight hours a day. There are times where I have to get up literally every few minutes/ multiple times a minute to chase him off her cage.

It's incredibly annoying to have to get up so many times in such a short period, and I work from home so it'd also incredibly distracting to my work too.

I've tried putting their cages close together, I've tried keeping them apart. I've tried having their cages literally right next to each other (with the door closed). I've tried punishing him by closing him back in his cage when he does it (and then he shrieks and shouts non stop because he wants to be out- also horrible when I'm in the phone for work). I've tried making him fly around the room to tire him out. I've tried having lots of toys in his cage. Nothing works.

I haven't tried to spray him with water when he does that, not sure if that will work?

How can I get him to stop?

*Monday edit

I got him a new toy yesterday which he has completely ignored, and have ordered another two new ones last night. I put a new box with shredded paper on top of his cage and his some treats in there which he also completely ignored. I also put a brightly coloured paper cup in his cage for him to destroy in the meantime which he's also ignored. I moved one or two existing toys around and even gave him extra food treats but alas.