Silicone is very safe and quite neutral. but the odor!
I am 100% positive medical or food grade silicone is safe. It has been used for decades and if it wasn’t safe, I’m sure we’ve would have heard about it by now. But is the silicone from vape manufactures medical or food grade? That I have serious doubts over. I do not know if the squeeze test performed in that video validates silicone or not, but can tell you without an ounce of doubt that my Vandy vape bottles display a filler compound as described in that video when squeezed. My other bottles do not.