Besides super glue, as some do not want to go that route, here is another option.
You also mentioned that you cut it off. This can actually slow the healing process as it will dry out the skin underneath the flapper. The best solution I found and experienced was to clean up the wound, which will hurt at first but is necessary, and then leave the skin overtop the open underlayer of skin. This will
The idea to promote healing, as it keeps is to keep the moisture in and protectsprotect it from infection and further damage. Bandage it up appropriatelyIf the flapper is damaged and letshould not be placed back, then carefully cut it healoff and use a moisture pad like 2nd Skin or even a bandaid that seals the tear.
Links that support leaving the flap on and moisture to help with healing:
Also, if you feel like you are getting to the point of a flapper, a preventative measure is to file it (or, what I do, sand it with a Dremmel) down and stop climbing. Let the skin heal stronger and use a skin strengthening balm like Climb-on or similar.