This research investigated the effectiveness of various particles in clearing smoke in enclosed spaces. Metal oxide nanostructured particles, conventional particles (i.e., corn starch, fire-extinguisher grade sodium bicarbonate), or water (electrostatically charged or uncharged) were sprayed into an enclosed experimental chamber filled with smoke. The times required for the light transmission in the chamber to reach 10% and 20% served as a measure of the effectiveness of the material in clearing smoke. Results indicated that the rate of smoke clearing was enhanced by spraying particles into the chamber. Of all the particles considered, the negatively-charged water spray was the most effective in clearing smoke and improving the visibility in the smoke-filled chamber. The smoke treated with charged water spray dissipated approximately 12 to 15 times faster than the untreated smoke. Also, compared with the solid particulate materials, the charged water spray resulted in a 3- to 13-fold increase in the speed of smoke dissipation.