None of my YS 4-strokes drip afterrun oil as their fuel system is sealed.

The Saitos OTOH are drool monsters - not from the muffler, from the crankcase vent. I used to close them up with a short bit of fuel line and a plug, but would always forget to remove the plug before flying. I now use a (somewhat) long piece of fuel line from the vent and slip the other end over the needle valve extension wire. The extra oil just stays in the line until the next time I fire the engine up.