smoke in a water bong, sandwiched between ashes.

a lot of people complain of these pipes and oil burners because the smoke reaches the mouth/throat too hot.. 

NAOH does not vaporize at temperatures you get from the lighter, but its possible that small solid particles from it may come with the other vapours, which could very well make the smoke harsh...  That is why using a bong with water would prevent this from happening because, appart from cooling down the smoke, also any NAOH particles would end up in the water and not in your mouth/throat.

also sandwiching between ashes guarantees that the smoke will only come from the dmt and not from combustion of the weed, so one needs to inhale less.