I use Weber lighter cubes, which are sold by Weber for lighting their charcoal grills.
Sold in places like Lowe's Hardware.
24 individually packaged cubes for around $6, the last time I checked.
The individual cubes might not remain airtight after you cut them out of the main pack, so take care to ensure that they are in a ziplock or something. I have had some in a ziplock for over a year, and they still work fine.
Anyway, they appear to be a lower cost version of WetFire. They actually burn a little bit longer.
They are cheaper.
To avoid issues with residue, I just use the cubes for lighting a little fire of twigs, and then I use that for cooking.
I guess some people don't like that, and so they can use the cubes alone.