Cigarette smoke smell

But some bicarb of soda in a small container and place in the incubator. Change every 3 or so days.

Also let the incubator air out.

 

Try cleaning it with vinegar maybe?

 

....Your chicks might need some febreeze for sure. XD

 

Just be sure that when you go to put the chickens in there that there is no trace of vinegar left as this might not be very good for them.

 

UV rays work wonders, if possible after you clean it out with whatever method, put it outside in the sun for as many days as you can, flipping it so both side get direct sunlight...

 

I think the fresh air would help too!

 

Yep, give it an initial scrub down to get rid of cigarette smoke residue, which is gross then let the sun work its bleaching wonders.
I use the sun to remove food stains and odors from glass jar lids. I like to save glass jars but wasn't able to always clean the lids (especially with foods like pickles and spaghetti sauce). But if I leave the lids out for a full day of sun, they are good to go. I can store everything from q-tips to desserts in them without having the contents smell like pickles, spaghetti sauce, etc.