If the hole is just to allow water to drain from a potted plant, maybe you can place a half of inch of gravel at the bottom (mixed with a little charcoal to keep it "fresh"). The water will collect there, letting the soil dry out properly. Fish tank gravel is nice for this -- it comes in small bags, it's pea-sized or smaller, and it's clean. I use it for all my plants, even with pots that have drainage holes.

My other approach is to use the pot with an insert that does have drainage. But then the plant needs to be taken out for watering.