If you put the cloth over the top and then put on epoxy, the cloth should just wick it in. It seems as if the cloth breaks the surface tension and allows it to filter down into the hole without trapping air.
John

: If you only have a few pinholes I think you should be able to get rid of them
: by gently and thoroughly heating the area with something like a heat gun
: and then apply a small amount of epoxy. As the area cools down it should
: suck the epoxy right in. I'm curious though. Are the pinholes located over
: a join, crack, or something similar? If they are over plain plywood I
: would suspect you have more than 2 or 3.

: Ted