Here is what seems to work pretty well. These injectors have needle bearing shafts which don’t seal real well, and were never really intended for EFI. When high idle occurs we have semi invented a way to help the situation.
Look at the pocket surrounding the shaft on both outside areas of the Bugcatcher.
Notice the bearing is deep enough to provide a pocket on the inside where the shaft goes into the bearing.
If you coat the shaft with Vasoline with a q tip, then fill the pocket with silicone, when it dries, you should be able to rotate the shaft inside the silicone since it didn’t stick to the shaft. So far several people have found success doing this, and in effect you created your own “Seal”.