De-coking a silencer?

I would like to get the carbon out of the small silencer on my Atco-Villers, I seem to remember it was a 'thing' to use caustic soda (soda crystals?) to clean out 2-stroke motorbike exhausts?

Hi mattblack,   in my bike days quite a good while ago 2 strokes were my thing, to de-coke the silencers I found that once removed from the bike I used to cut in half a potato that was large enough to press over the  end that the exhaust pipe would fit into not the exit end of the silencer this made a good seal so a caustic soda /warm water mix of around 50/50 was poured in to exit end of silencer and with it stood upright for 24 hours it would usually get rid of the carbon, of course depending how thick carbon was.  But wear gloves and an eye protection as its nasty stuff that is emptied out.   Of course if it the usual Villiers type exhaust a plastic box with the soda/water mix in could be used as a bath but this will not do anything painted any good.
Don

Thanks Don, I didn't think I'd dreamed it...

It's the small silencer you can see in the photos of my engine so no problem giving it a bath.