Sealing Clean Out Plug

[steelhorse454]

So I know this has been previously discussed, but what are the updated details of sealing the clean out plug properly?
I purchased a toilet wax ring and went around the rubber on the plug by hand, but I'm getting more water in now than before.
Previously, I used Yamashield lubricant and it did OK, but some water was still getting by.
Anyone else have any updated tricks for a total seal ? Or, is this not possible.

 

[Cambo]

water comes up through the clean out tray drain put a cork in the drain hole and test. Even better test put a cork in the drain hole and fill the clean out tray with water and watch how much water pours out the transom drain




Installed a one way valve it helps

 

[David Martin]

My 2013 sx240 came with white lithium spray grease on the plugs and metal tubes......the dealer use it during service for the original owner 7 years......I continued now for 4 years in salt water. Plugs are original 11 years old and mine stay dry. I spray the plugs and tubes about once a month.

The next benefit is the metal tubes are not corroding at all, something to consider since those tubes are non replaceable....no part available.