He promised to be more careful with his toys from then on.
What happened to him that made him promise to be more careful?
I sent him to the woods after he kept breaking things around the house. That taught him a lesson real fast.
Although toys are expensive and it's not good to destroy things, punishing someone by sending them to the woods is dangerous. Especially if they are young, they could have been seriously injured. Instead of doing that, you should punish them in other safer and healthier ways like sending them to their room.
The woods are clearly an effective punishment though, and it's not like there's bears out there. It's just in our backyard.
Even though it's not far from your home, the woods are a dangerous place for a child. He could get lost or run away or trip and hurt himself. I really don't think you should use the woods as a punishment in the future.