After trimming with sterilized scissors, I used copious amounts of stop bleed powder--which mostly helped but it still kept flowing! I read that you can use tiny amounts of super glue (like with humans). This also helped.
Finally, after all of that stuff--along with ice and pressure--the bleeding was mostly stopped. When dabbed with a clean white cloth, it was only slightly yellow (no red). So I isolated him in a big tub with some bedding and covered the top to make it quiet and dark.
When I checked on him an hour later, he had opened it again--! So I dabbed at it to wipe up the blood but it was gummy and didn't wipe up or make the tissue red.
What I want to know is: will he be okay if I keep my eye on him? When is it considered an "okay" amount of blood? Last time I checked, he wasn't actually bleeding--just had crust mostly (scabbing) and that one patch of gummy ooze. Not even dripping!