I put a splash of 2 stroke oil in the petrol of my bikes/generator/lawn tractor etc. It lubricates the inlet valve stems plus it leaves an oily residue in the carbs when petrol evaporates off. It also adds a hint of lubrication to the bores on the inlet stroke, so not just burnt off.
The minimum ratio for actually running a 2 stroke on petroil mix has been shown in tests to be 200:1. But as this is just a supplement, a splash is probably ok.