Never acknowledge an apology.
An apology tips the balance of power in your favour. When you acknowledge an apology, you return that power to the person making the apology. Instead, remain silent or continue talking as if the apology had not been given. This creates an imbalance, that destabilises the other party like the set up to a Judo throw.
For truly advanced Julianism followers, counter an apology with a stare lasting at least thirty seconds. If the person making the apology holds eye contact for this long, break into a gnomish grin and hold for a further thirty seconds. If the person making the apology makes no reaction, tell him or her to go do the washing up.