Hmmm, okay. I wonder if a dermaroller might help here.
If you don't know, a dermaroller is a device with small needles embedded in a small barrel-shaped roller attached to a handle, which is rolled across the skin. Needles penetrate the skin to help with product penetration (mostly anti-aging topicals) or collagen formation. Needles range in size from about 0.2mm (very, very, very short) to up to 3mm (quite long and scary).
Short needle dermarollers are benign and almost fuzzy-looking; long needle dermarollers are freaky-looking and somewhat resemble a medieval weapon. LOL
Short needles are used to gently penetrate the epidermis to help with product penetration; longer needles are used to "wound" the skin through to the deeper layers of the dermis in order to stimulate a healing reaction to generate collagen and eliminate wrinkles.
I wonder if using a short needle dermaroller (about 0.25mm) would make the b12oil more effective (by virtue of better absorption/penetration through the skin)? You'd have to be very careful with cleaning it every day, because a dirty roller can carry staph and other nasties, but I've re-used many rollers many times with no problem. It's all about careful sterilization right before and right after each use.
If I wasn't so hooked on my injections and was looking for an alternative to sublinguals, I'd give it a whirl.
Just thinking out loud if anyone wants to experiment. With the right B12 product it could perhaps be a comparably potent delivery alternative for people who don't like or can't get mB12 injections.