DMSO requires a little more than an IV dose, but if one does it correctly, less than an oral dose.
I've done it before; it stings a little, but it gets the job done. One of my favorite ways to take things that normally upset my stomach. Got a bottle of it sitting on my desk.
I've had some of this for years but always worried about what else might sink in with the intended payload. I'll have to look into it more seriously... I've got plenty of veins but it'd be quite novel, even without the white phosphorus