"I've been treating it with salicylic acid combined with a pumice..."
Using a pumice stone shaves off the dead tissues as well as the live ones, including the virus causing the wart. It tends to spread the virus around in an area that is being traumatized. Don't do that.
I have been successful using a salicylic acid "plaster" applied directly to the wart, and then Cutting away dead tissue with a Sharp scalpel. Clean the scalpel with alcohol after each use. Get a new one when it gets dull, about three trims (I bought a handle and a box of blades). It can take up to six months. I kept hiking the entire time.
The "plaster" looks like moleskin and is adhesive. I cut it to about 1/8" x 1/8" (small), apply it after a shower and "trim", and then cover that with a 1.5" square of duct tape (otherwise it will slide out of position). I shower with it in place, then after about 4 days, remove it, trim, and repeat.
A friend had an injection and was done in a day, running in a week.