I then prized out the bit of medicated gauze and tried to rinse the area with bottled water. I've since read that hydrogen peroxide is the way to go.
The yellow stuff in the photo below is mostly dead tissue.
I didn't take any photos at the hospital on Monday or Tuesday. But here is a pic from this morning when I cleaned it myself again. No more swelling, no more red skin ranging from my elbow to my wrist, and no more worries about "losing my arm", "infection reaching my heart", or death. As various comments from medical parties had me worrying. In the pic below I'd just put hydrogen peroxide on the thing, hence the bubbles.
Don't sweat the petty things, and don't pet the sweaty things.
—George Carlin