2 ideas. Guaranteed to work. Both of them not very likeable at first glance.
1. Get a ton of Amano shrimp.
I'm talking 200 in a 25 gallon tank. Getting 20 will not do anything to the Clado.
2. Find a way to run a perfectly clean planted tank.
You will see the Clado gradually dwindling away and coming back if you drop the ball on maintenance in some way. Play this game till you get rid of the Clado. By that time you will be a planted tank guru, guaranteed, and most topics here will annoy the hell out of you.
And there is a 3-rd, very likely scenario: You drop the infected plants in your tank and the Clado dies off quickly. That is not an uncommon thing.
The bleach is an obvious approach but you got to be careful with the concentration, duration, and neutralizing. And it does not work every time. Also fine leafed plants can't endure that kind of treatment.