storing values safely in scripts?

I've been playing around with int values to store how much "sand" there is in a sandpile or container, but I was storing the values inside the models in the workspace and from what I read it is not a good way to do it. so is this code better or is it not safe enough when the script is under the model in the workspace?

local Material = script.Parent.Material 
local value = 0 

Material.Parent.CollisionDetector.Touched:Connect(function(hit)

    if hit.Name == "DropOFF" then
        Material.Transparency = 0
        value = value + 1
        game:GetService("Debris"):AddItem(hit,1)
        print(value)

    end
end)