Use plenty of lube to drill the hole first, then fill the hole with lube, so as the tap goes in, the lube is forced out, bringing the swarf with it. The swarf will also stick together, making it FAR easier to remove it afterwards. This also makes the sides of the hole stay clear (Assuming it's clear acrylic), and not go smeary. Ideally don't do the screw up tight until its the final putting together. When it's put in tight, the acrylic sticks to the screw, so everytime it's tightened the acrylic wears away. Hope this helps