So I know there are a lot of tips out there regarding odor, and without going through a big long list, none of them worked for me. For the first few weeks, I tried adding all kinds of things to the bag to mask/neutralize the odor, no success. Then I tried internal deodorizers-- still minimally effective and expensive as all...
By swiping my fingers around the appliance, I figured out the odor was mostly seeping from the seal between the bag and flange, from the juncture between the bag fabric and plastic ring, and from under the Hollister floating flange. Being the jury-rigging type, I decided the best thing I could do would be to reinforce these areas so that odor could not get out. After trial and error, I developed a series of modifications that add about 10 min to my bag change routine but block any detectable odor for 4 days or more.
To reinforce the flange, I use the 5/8 circle on a measuring paper as the INSIDE measurement for 2 half circles that I cut out of a double layer of duct tape. I cut them out so they're about as wide as the flange, then fit them under it on the outside. Then I cut smaller half circles from the tape I have left and fit them over the same area on the inside.
I put some regular bathtub caulk around the place where the flange fabric meets the ring. Usually, I let it dry overnight before I plan to change the bag.
Finally, I put superglue in the threads of the bag before I attach it to the flange. I don't have to change the bag more often than the appliance because like I said, I have no odor for the duration of the flange when I do this. It also does quite a bit to prevent leaks, which I cannot deal with having.
It's kind of complicated, but modifying the bag in this way is the thing that allowed me to feel like the ostomy has no effect on the quality of my life. I couldn't actually eliminate odor any other way, and I had to buy a lot of crap to even try. Now I only use some internal deodorizer if I plan on eating garlic or something. I can bend my face as close to my stomach as it will go and not detect any odor (besides the caulk at first).