What's best for feline acne: HClO, Chlorhexidine, or other treatments?

I think you are doing too much at once and you have unrealistic expectations as to how quickly this should resolve. Less is more in these cases. Remember, this is not an ailment that you can cure - it is only one you can manage. I suggest you pick one treatment. I recommend using the benzoyl peroxide once a day. The mupiricin is likely what is causing the discoloration and it is only indicated for use if there is a concurrent infection (same with the Chlorhexidine). There does not seem to be an infection in this case. Continue with the steel bowls. If after one week of using ONLY the benzoyl peroxide and you are not seeing any improvement then feel free to post again and we can see if we can help you more. ( https://www.petcoach.co/cat/condition/acne/ )

Use a warm compress to soothe the area. Clean daily using dilute chlorhexidine or a mild cleanser containing benzoyl peroxide. Rinse the are thoroughly and pat dry. Try not to get any in his mouth. If the acne doesn't resolve, have Travis examined by your veterinarian.

Mild cases of chin acne are sometimes treated with a benzoyl peroxide shampoo or gel (2.5% concentration) daily until resolution and then treated one to two times weekly. I am not sure what products are available in the UK without a veterinary prescription, as the human over the counter benzoyl peroxide products are often a higher concentration and can be irritating to pets. Some products may be found online such as this https://www.chewy.com/vetoquinol-benzoyl-plus-shampoo-dogs/dp/109500?utm_source=google-product&utm_medium=cpc&utm_campaign=hg&utm_content=Vetoquinol&utm_term=&gclid=CM7qoYmvmtQCFQYwaQodZOEJtw&gclsrc=aw.ds or Pyoben Gel or Oxydex Gel. Sometimes these guys also need topical antibiotics such as Mupirocin, which is prescription only in the US. Severe cases may need systemic medication.

I don't think it is skin mites. Blackhead (chin acne) is pretty common in cats and can be treated with daily Chlorhexidine solution OR you can use a topical human topical benzoyl peroxide gel 5%. Trimming away any long hairs is helpful as well.

In this case (severe) of feline acne a check up would be absolutely needed as antibiotics are required. Anti-septic shampoos are required as well like benzoyl peroxide facial preparation or an antiseborrheic shampoo. Mupirocin ointment is highly effective in many cases.

You can clean the area with a cotton ball and hydrogen peroxide or you can use acne pads with benzoyl peroxide if you have those. Do it morning and night and it should clear up. If it doesn't, have it seen by your vet in case she needs something else to help her heal.

You should use a plate for Fluffy’s food and clean it frequently since oils from food or a reaction to plastic bowls can lead to acne. Occasionally medicated benzoyl peroxide wipes or ointments like mupirocin are needed to help with acne. Depression shouldn’t be related and can be a sign of a number of diseases so if it continues and you’re concerned your should see a veterinarian.