Possible Treatment for Dettol Burn Scar on Face?

I am not able to give you a recommendation based on the photo shown. Most likely, if it is a first or second degree burn, it will heal on its own without scarring. Depending on your skin type, you may however develop darkening of the skin after the burn, called post inflammatory Hyperpigmentation. This can be prevented by use of sunblock and Retin A and bleaching creams. My advice is to consult with a plastic surgeon or dermatologist. Good luck.

I would seek care by a professional such as a dermatologist or plastic surgeon.
Over the counter preparations with silicone and sun block may be beneficial.
Use of bleaching agents and steroids should be montiored and prescribed by a medical professional.
I am not a fan of mederma, aloe vera, vitamin E, etc.

It appears that you had a first or, at worst, a second degree chemical burn. The most frequent consequence is a pigmentary alteration - either depigmentation (a white spot) or post inflammatory hyperpigmentation (a dark spot). You will most probably not have a scar. The best advice at this time is to stop putting anything on it except an high SPF sunblock every day to avoid the pigment changes. If they do occur, consult your dermatologist before seeking home remedies which may worsen the problem.

It is difficult to tell from your photo, but I would go for a consult with a plastic surgeon to be evaluated. SInce it has healed, you may need nothing at all.  Sometimes nothing is done except to watch it. Sometimes if the burn is deep silicone sheeting or other topical agents are used to treat the scar.