I don't think rubber washers between the camber plates and the car frame will do it, although its worth a try.
The factory struts come with rubber isolator rings at each end of the coil spring, & I expect that will do more to help.
The camber plates are connected to the shock piston, and that only touches the road wheels through the piston rings on the piston end, whereas the spring is steel on steel between the body and the suspension now.
Both put noise through the shock shaft into the camber plate, but your rubber washers will need to be on both sides of the camber plate bolts and not done up hard so they float a little.