I agree! I have also decided to make my own dampeners, to be used to connect the whole platform of my octocopter (in the building process) to the struts holding the motors.
I am adding the photo of my latest developement in anti-vibration mounts. Now the octocopter looks like this (see photo).
I used 2 mm thick nylon sheet, from which I cut by hand (with great difficulty, lol) the disks and the crosses. The O rings are 27 x 17 x 5 mm, hardness 70. I tested each mount with 1 kg in compression and 3 kg in traction: NOT A PROBLEM! The octocopter, with battery, camera and FPV, ready to fly, will weigh 1850 grams