Could try getting at it with a bench wheel and polish it to death but it may be beyond that.
If you really wanted to keep that tip you could remove it and maybe get it plated? not sure if this is a possiblity but could be an option. for the aggro probably easiest to get a good 2nd hand one.
tbh, you can see the inner metal of the exhaust starting to delaminate/exfoliate which isn't great. In the long run, may be best just getting a decent stainless cat/axle back that will last