The door seal on my ES-P has sprouted several pinhole leaks in the region where the two ends of the tubing are joined together.  I contacted the manufacturer, and was told the seal is made from layers of dacron and silicon.  This repair procedure is my adaptation of what he told me about fixing leaks

Lightly sand around the area of the leak
Clean area with acetone
Poke some rtv silicone into the pinhole.  I've found that a toothpick works well.  I've been using DOW 3145 adhesive/sealant.
Let the rtv fully cure
Inflate the doorseal with the door open, keep inflated for the following steps
Spread a small amount of rtv around the area of the repair, and press a small patch of peelply into the rtv
Spread a bit more rtv over the top of the peelply to seal the peelply and its edges.  An ice cube works well to smooth out the rtv & peelply combo
Keep the seal inflated while the silicone dries

The initial poking of the rtv into the pinhole fixes the leak.  The application of peelply keeps the inflation/deflation cycles from reopening the pinhole.

I've repaired numerous pinhole leaks in my plane's seal; these repairs have lasted so far for 200 flying hours...no pinhole has reopened yet.

-isaac
ES-P N7842K