There are a ton of ways to alter the V(5) chord. We can # and b so many extensions it’s crazy but here’s one way to do it using a diminished arpeggio. With any idea like this, to use it I personally have to connect it to something I know. So we can start a diminished arpeggio:
-half step above the root
-on the 3rd
-on the 5th
-on the 7th
of the V chord. This turns it into a Vb9. I like this trick and I hope you do too!