Легче и проще: новая ваза, новая форма, новая текстура. Из пенопласта, бутылки и цемента. 

Advanced technology. A little faster and a lot easier.
Plastic bottle, Styrofoam, cement and any glue that sticks Styrofoam together and is not afraid of water. I have acrylic, waterproof "crazy Velcro" :)
For cement mortar: 1 part cement : 2 parts sand. Add a solution of PVA glue and water to the dry mixture.
Not necessarily 1:1, you can 1:3 and even 1:5, but Glue must be present in the water!
The density of the cement mortar is visible in the video:
for modeling - thick, like dough
for installation of fiberglass mesh - like thick sour cream
to apply the texture a little thinner, but not to spread.
Paint - rubber. Two layers of grey.
White for the manifestation of the relief: rub a few drops with a sponge and apply without pressing in one direction.
The whole job took three days.