Yes. Bottom up. I experimented with the top-down gimmick one season, and it works, but I really didn't see any point in it. Note that folks like Poindexter, dealing with the smoke Nazi's in Fairbanks, may have a legitimate reason for it. But for the rest of us, it's just a more tedious and less reliable way to do what folks have been doing for tens of thousands of years, if not longer.
WRT chemicals, SuperCedars and fatwood are the only two I've ever purchased, and both are completely free of any chemicals that will harm your cat. The SuperCedars are just cedar sawdust compressed into a puck with a paraffin binder. The fatwood is just high-resin conifer stumps split into pieces the size of pencil.
In Boy Scouts, Order of the Arrow, we were allowed two. If you couldn't get something lit with the second, you slept alone in the dark. But in my own living room, with no wind or rain, it's pretty rare to need more than one.
Side note, my wife keeps buying these stupid Scripto grill lighters. She likes them for lighting deep jar candles, and thinks they'll be useful for lighting stoves, especially since none of our local grocery stores carry regular wooden matches anymore. But I'm pretty sure I've never gotten more than a dozen uses out of one of those grill lighters, before it stops functioning reliably. I would guess that nearly every one of those I've tossed in the trash still has 75% to 95% of its fuel remaining. This is a good example for some of our threads on wasteful single-use plastics, as these lighters are very nearly so. My matches never fail.
All this talk of lighters just reminded me that I have one of my grandfather's old stainless Zippo lighters sitting in a cupboard in the garage. Might dig that out today, put a new flint and fuel in it, and put it in the glovebox on the tractor. Lighting the outdoor firepit on windy days to burn off splitter waste is one place where a lighter is sometimes better than a match.
I did this for several years. Now I just leave the cedar big, and stack it in the rack I used to use for kindling, to be used to burn down oak coals before the evening reload.