I'm sure it's not the proper terminology, by my silk pleco has this sore on
his belly. It's no specific shape, offwhite in color, grows about .5mm per
week.

Now I've read about this somewhere before, but for the life of me, I can't
find it again. He's a very active pleco, out all hours of the day diligently
working away. The sore originates where his belly rests on objects. 95% of
the time he's on the glass, rarely comes off the glass.

Naturally, if this was some other fish, treatment of melafix and/or salt
does the trick to heal the wound, or antibiotic if it's infected, but this
is a pleco, and the wound is constantly irritated just be the way it sits.
It's location is also not pleasent, most unprotected spot on a pleco, and
close to organs should it get infected.

Only thing I can think of it build a ghost trap out of a 2l pop bottle and
trap him for a week or so until the would heals, assuming the shape of the
bottle would prevent constant rubbing.

Any ideas?

Cheers