Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am sorry to hear that your pup rolled in charcoal lighter fluid and the scent remains even after being bathed twice.
The trouble with this product is that as a petroleum product it is easily absorbed across the skin and gets concentrated in the oil glands as it easily mixes with fats/oils and can cut through them. Similar to skunk spray scent it is hard to remove once on the skin and having any sort of time period to be absorbed.
It's important to use something that is a degreaser and that will flush out her oil glands to have the best chance of getting it off.
The best way to get the scent out is multiple baths as soon after the pup is exposed as possible. The longer the scent stays on your pup's coat the more difficult it will be to remove, but even now it is worth trying.
A homemade shampoo mix for this is:
1 quart of 3% hydrogen peroxide
1/2 cup of baking soda
2 Tablespoons of dishwashing soap (Dawn dishwashing soap seems to be the best)
Mix all ingredients together and use immediately. Do not try to save the mix as it will become unstable.
Lather well, let sit for 10 minutes and rinse well with cool water.
Do not use hot water as that opens the pores and the scent will settle in her pores and oil glands even more.
Repeat bathing until the scent is much less apparent.
This mix does have peroxide so expect some coat bleaching. Avoid the eyes and mouth, as peroxide is very irritating and can cause corneal ulcers and nausea if ingested.
Nothing will completely remove the scent, and expect your pup to smell more when she is wet, but this should help tremendously.
Please let me know if you have any further questions.