I use one when I need to. Prills work great but Ive also had great luck with sulphur "flour" powder. Shut ventilation and lights off while burning. Do not spray ANYTHING on the plants just prior or after trtmnt or they will crisp up and fry.
how long till it's safe to be in the room? how long does the sulfur smell linger?
Well, It's pretty safe once you stop fuming it but the smell lingers for a WHILE. So shut it off after desired burn time and let everything marinate as long as prescribed. Next ,turn your ventilation back on and let it evacuate the smoky fumes for about 30 minutes [my timing] then open the room up and go in cautiously at first. Ok so now wipe down everything metal that is ferrous as it will corrode . Light hood, mounting brackets ect... wipe off the bulb and kick it back on.