I never find a problem with good coke or pepsi can alc designs and ive tested just a few. This is a greatdesign and super easy to make
https://youtu.be/ui8t3pivqtkFor my wood stoves, even double wall gassifiers, eucalyptus wood still puts out a bit of a coating on the pot even when youve got a non smoke flame, its the oils.
So for both, i just use a really lo tech low enviro impact solution - use a light weight plastic bag you buy your woolworths veg as a pot cover - just wait till pot is cool (test with finger) and pop in the empty plastic bag. This lasts about quite a while depending on how much care you take. Zero weight - recycle the bag when finished at ww in the recycle plastic bags bin. Altern use one of the bread bags (not the one you use for feet covers!).