How do you clean out 2 stroke exhaust systems?

[mudguard]

I have had my 2 stroke expansion chamber and silencer hanging up in the shed for a month ( new coat of paint ) and just put it on the ground now and some black oil dribbled out.
Is this normal??
Is there a method of cleaning the exhaust system and what do you use?
Is there any advantage in doing this (any better performance ) or should I just leave it as is? 
 

[JohnnyO]

Probably should have burnt it out with the oxy torch or acid dipped it before you painted it.

[DR]

Could try washing it out with caustic soda or something like an alkaline degreaser. The paint may stay. Take a good look inside, unless it's got obvious carbon build in the visable in the header or stinger sections and doesn't seem overly heavy for what it is then probably not worth too much trouble as any small amount of residual oil will soon burn out after start up.   

[Tim754]

Don't try black gun powder from an old muzzle loader....    it splits the seams... and ya deaf for a week....

[Captain Bilko]

Get on the main more often......