I have the standard rubber flap that scorpion fit https://www.cquip.com/shop_585581987.php
I also have a bung that goes onto the inboard end of the pipe as they don’t work and are right on the water level.
In addition I added an in-line NRV scuppers. Still doesn’t work and I always need the bungs. Luckily I also have a lower deck drain operated by bilge and the higher ones are for a lot of deck water.
I bought some ping pong ones but the sink test convinced me they will also gather debris and fail.
Last result is a US company called scupper buddies. I haven’t fitted these yet but are a small spring to add tension to the rubber flap scupper.
In reality an elephant trunk may be better functionally although I detest the look of them and have never had one.