Plug down nozzle holes?

I am wondering if anybody does anything special to plug the down nozzle holes in fuel heads. Silicone or teflon paste or nothing? Aluminum or brass or steel? Anything to avoid. Thanks.

 

we used a regular steel 1/8" pipe plug with a little Permatex pipe sealant. it seemed to work pretty well for us.

 

plugs

I used the brass ones because the aluminum was alittle too expensive. pipe sealant on the threads, just to feel better.