I have been soaking my driftwood for 3 days now and they still haven't sank. What can i do to weigh them down? I don't have enough sand to put on top of the wood is there anything else i can do? Thanks in advance for the help. and the driftwood i have was found locally in the river and has been cleaned and boiled, but just won't sink. I really want to use this wood though, it looks really cool.