Hydrofluoric acid is potent poison and skin rot agent. As a organic eating acid, it is weak.
It does not kill you by burning instead of seeps into the skin, like DMSO, into fatty tissue, and causes calcium to precipitate.
This causes lysis of cellular matter and I believe clogs your heart.
In a gel form, it is probably safer, because it does not penetrate the skin as rapidly, you can wipe it off to minimize exposure, but expect to lose flesh, like a spider bite, at the very least.
I would recommend through wiping rather then washing. If you spread it out, the contact with your skin is larger. It is surface area dependent. In-fact I would recommend carefully scraping it off with a razor as to minimize spread before smearing it around to get rid of it (keep in mind the HF molecule will already have diffused through your skin some what and you should get medical treatment).
Keep in mind, the dose absorbed through inhalation is rather small, compared to the massive dose you would receive with skin contact. Don't take the fact that breathing some fumes won't kill you as it being safe for contact.