wood from creeks as tank decorations

[untree]

A buddy of mine has collected and cleaned pieces of waterlogged, semi-petrified wood from local creeks as decorations for his tank. Some of these pieces look pretty amazing (hollowed out tubes of twisting, gnarled wood), so I'd like to do the same for my tank. However, I am a bit concerned by the fact that these are ancient cores from pine trees, and the tank water might leech some of the resin out of them. The outer coatings are very wood-like, and seem almost like they might seal it in. Does anyone have any suggestions about using these, or possibly ways of treating them to make them safer for use? I attached a picture of one that i found recently in a creek.

[Gimli]

I heard boiling them for a while(no idea how long but a while) helps. It also allows it to 'sink' to the bottom.

[untree]

yeah, i've heard of using that technique for normal wood, but are you sure that can be done for the resinated pine cores? i was worried it might make the resin liquify a bit and soak the outer wooden layers of the pieces with resin. they already sink in water, too, since they are so dense. and to top it off, these pieces are all quite a bit larger than the largest pot i have that i could boil them in. i'm considering giving up the idea of using them, despite how nice some of them would look in the tank.