IMO, and I'm not a doctor, the best way to handle blisters, is to prevent them.
If you get a hot spot on your heel or somewhere else, put your ego in your pocket and stop!
Take time to put a simple piece of tape or a bandaid on the hot spot to eliminate the rub and prevent more problems down the trail.
Up until last year, I had gone years without a blister.
Last April 2019, while camped at bright angel campground, grand canyon NP, I took off my socks to walk around in my trail runners and take pictures. Unbelievably, I didn't notice my heel was being rubbed until it was too lake and I had a huge blister.
Fortunately, I was able to just tape it down and drive on with no pain.
Remember that it is not only friction that causes blisters but also PRESSURE. Adding a layer of anything to a hot spot or a blister can make it worse. NOLS always recommended using a thick molefoam patch made into a DONUT to prevent added pressure on the wound. A broken blister is an open wound and needs to be treated as such. I've used this method for years then found Second Skin gel that could be put directly on the blister because it is malleable and seems to not add pressure. It also lets in healing air.
I'm going to say it again, if you feel a hot spot, STOP IMMEDIATELY, and tape it, before it gets worse. I strongly feel this is the absolute #1 thing you should do!!!