The silicone that I buy has a thin cardboard box, so I just cut out a piece of it and coat it with the silicon. I generally let it get tacky before I install it. Thats generally about 10 minutes or so of cure time.

This method also works great around the nipple where the hose goes to the carb. I have had 2 TTpro46 and the both leaked a little aound this spot. I used the cardboard and silicone and it hasnt leaked since.