Clean thoroughly with homebrand napisan. Pull out the airlock grommet, tap, o'ring under the lid and wash these too. Use a recycled toothbrush to clean all grooves and threads out. Rinse thoroughly and store upside down with the lid off.
Sanitize with iodine prior to next use.
There are many products better than sodium met available to the homebrew market, use them instead. Save the sodium met for adding to your mash to stop HSA.
Snap taps are much easier to clean, they pull apart so all surfaces can be cleaned. Have upgraded all my fermenter taps to snap taps.
Sodium met is used in winemaking where they are a bit more tolerant of wild bugs. In winemaking, pH is much lower (less bugs can grow) and the wine is fermented out fully (all the sugars are used up, beer yeast only consume 65-80% of sugars) and there is no remaining sugar available for bugs to eat. In beers, the residual complex sugars are still a very attractive feast to bugs.
So, if you really love the smell of sodium met and the idea that you may get an infection, keep using it.