There's one fantastic trick to suppress any unwanted memories. Basically, imagine physically grabbing the memory and locking/sealing it in something small, such as a safe. Then crush that small safe to make sure it's harder to open and lock it into a larger safe. Now blowtorch the safe to make it harder to open.
Next, take that larger safe and blast it to some far off corner where you'll never find it.
No, you don't need a mind palace for this trick to work. You don't even need to be good at imagining things. It's the thought that counts.
The goal isn't memory destruction, it's memory suppression. This is highly effective at dealing with a multitude of feelings such as fear, disgust, grief, and embarrassment.