Never boil any driftwood that you want to have around for a while. Boiling breaks down the cellulose cell walls and causes the driftwood to break down even faster. Long time immersion, as in nature, is still the best way to cure driftwood. Floating pieces can either be tied down in water buckets until they become waterlogged (remember to change the water frequently) or can be attached to granite tiles or terracotta with ss screws to keep them on the bottom.