Forgive me for posting this, but I've googled it , so this is my last resort, I got a 1tb slim pro, about 3 years ago, and as long as I can remember it sounds like a leaf blower, even on start up once game loads, I read some games the ps4 can't handle, and you have to live with the noise, as it sounds so loud on start up after selecting game, hasn't had time to get hot. I feel like taking a hammer to it. The only reason I can't wait for the PS5 is less bloody noise.
I can relate. There are times when I'm playing Ghost of Tsushima and it sounds like my PS4 is trying to take off.
But cleaning can definitely help with it. Compressed air and a small paint brush for the little nooks and crannies are my go to cleaning regiment about once a fortnight.