I used to have a problem with charcoal for the incense burner. In Russia, most practitioners use church charcoal for censers. It's not very good quality. My Guru advised me to use charcoal for a hookah. Coconut is best. I also bought a special device for lighting hookah charcoal, which is a small electric stove with a metal strainer in which charcoal cubes are placed. Coal burns very well. Then, with special hookah tongs, I transfer the burning coal into a cast-iron censer filled with sand (a layer of sand at least an inch thick). I put incense or herbs on top of the charcoal. Everything is fine, no problem.
I used to get self lighting charcoal discs 40mm from the international market, but the last 2 times I went they had the Not-Self-Lighting ones. Omg. I tried holding them over the gas stove. Nothing. I tried using the little torch lighter that I normally use to light the self lighting charcoal and when that had zero effect, I used a bernzomatic torch, the kind you can to solder copper pipes. Still wouldn’t light. I mean I literally opened the plastic and put the fire to it and it REFUSED to light. Here in Mexico you can buy self lighting charcoal discs that are freaking huge and they light basically with a match.
our long suffering peer here may benefit from a few things.
I’m not a Wiccan so I don’t have this obsession with “cauldrons” but I have aquired several cast iron ones over the years, including one that holds about 8 liters, it’s huge. I also bought a small one with a lid like a mini dutch oven, when I lived in a tinder box in the

i was paranoid about immolation of mi casa, so I got several pieces of scrap ceramic tile and stacked them to set the hot kittle on top for insulation. If any kind of conflagration got a little bit too robust, the lid went on and the fyre was extinguished.
nearly all of my incense sticks are burned in a huge, heavy glass cup that I got second hand. Fill it with regular table salt and put your stick in there after you light it. Yeah, the ash has a tendency to want to migrate to the surrounding area, I suppose you could put it on a glass plate but I just factor it in to my cleaning routine. I think about what our ancestors would have been doing in a medieval hut, cave, or tent in Arabia, etc. to put it in perspective for my modern sensibilities. (“This is my specially consecrated magical sword and athame, it is never used except for magical rituals” vs “this sword that I carry every day and used to slay Wulfgar the Strong is what I’m going to use, and hand me that butcher knife we used to slaughter the chickens yesterday, I need to cut some herbs”).
A friend gave me a little sort of melting device, it uses a tea light and has a small brass bowl above it, i use it for oudh aka agar wood aka “aloes” And put a piece of aluminum foil on top if i want to use resin. The smell is much more subtle than if I burn it on charcoal and, obviously, it doesnt set off the smoke alarm like resin on charcoal.
for OP, I recommend using a small pair of tongs, you can actually make your own with a piece of wire from a metal clothes hanger, and use that to ignite your self lighting charcoal either over a candle or with a lighter. You will need to let it burn until it stops sparking and smoking before you set it in your burner, this can take several minutes. For gods sake don’t drop it, you might want to do the lighting over a sink or at least a metal pan. Once it stops smoking you can add your resin or herbs. For smoking effect you can dampen your dried herbs a little bit otherwise they tend to burn up very quickly and not make much smoke. A small mister bottle like for perfume with some distilled water works great
as others have said, even a tiny granule of resin usually puts off more smoke than several sticks of incense, it’s easy to choke yourself out even with an open window. Mortar and pestle does a great job of reducing your resin to a reasonable size, even powdering it if you want.
i’m kind of mixed opinions about smudge sticks, I don’t have any evidence that they were historically used by American Indians until the late 20th century. They aren’t very practical to me at all, while charcoal discs are extremely practical and effective. I suspect that historically people just took coals from the fire and put them on a piece of shell, metal or pottery and then added their herbs and resins, whether it’s European, Asian, African or the different cultures in precolumbian americas. The Asians seem to be the pioneers of stick incense though I don’t know when they first started being used there.
don’t get discouraged, experiment with a few things and try to be safe