This is completely normal. It happens to all kinds of driftwood. The "slime" are bacteria in groups that build up on the wood. I threw in a couple snails when I had driftwood and they took care of it real quick. So you don't have to get rid of it, it just looks unattractive. It will go away in a couple weeks if you just leave it.
My tanks (so far
5.5 gallon Planted Dwarf Puffer tank (2 Dwarf Puffers and a lot of RCS!)
16 Gallon Planted
(GBR pair, 3 amano shrimp and a whole bunch of snails!)