Hey Miles, I am 1+ Phil's answer here. one right way to do this would be to get it on the ISP line, and prevent it before it gets to you.
We have Colt IP Access, and I am persuing their IP Guardian.
I know Colt services are quite globally wide spread,
If you are high up on the risk model, or your fallout risk is damaging, maybe you might want to look into Colt's solutions.
here is there info page on it.
https://www.colt.net/wp-content/uploads/2019/07/IP_Guardian_Datasheet-English.pdf