I've consumed straight alcohol while on a Ketogenic diet and have still had good results. As indicated, the body will stop burning fat for fuel and switch to alcohol however it will switch back once used up. The key is to make certain that there's a negative calorie deficit. Since the alcohol is taking the place however of the fat that was being burned, I count those calories and include them in my daily fat macros so I stay on track.
I will add though that I've had better results during alcohol free cutting however my job is stressful as hell so sometimes I can go 3 - 4 months without a drink and other times I can only go about a week or two.