Let me try to be more clear: after some time, in a dead organism almost all the cells are so degraded that they're unable to do anything (even if we supply them all the energy and nutrients in the Universe). The cells that happen to be not very damaged are so scattered that they will be unable to work together (even if we gave them everything they need). And if the cells don't work together, we don't have an organism (and do complex things, like grow).
The second point is: even if we provide everything to an organism, it can't make a thing they were not capable of. So, I may accept (although I don't like the following idea too much) that if we use our Psy powers carefully in some termites we might be able to command them to degrade faster a wooden chest. We may even command micro-organisms to accelerate the degradation of a rock. But, the way I see it, that wouldn't be fast enough to use during a battle.
In a battle I would want my attacks to work fast, so I want something that affects my targets, either by dealing them physical damage or damaging their brain. The way I see it, growing stuff is usually too slow (perhaps with the exception of the Tig).
In the orb suggestion thread, we were discussing about the ability to remove immunity against mind attacks on objects. The discussion derived to how mental attacks work and if, with the help of an orb, they could be expanded to affect objects. So, I think it would be more fruitful to have more suggestions that could be applied to all objects and not only wooden ones.