We had a "little things" rule. No toys that DS could choke on could come out of her room, and when she played with them he had to be out of her room, and not able to get in. When he was in bed she could bring things out, but if he woke up from a nap she would put them back. It doesn't torture them, and it only lasts a short while. The other thing was that she was able to teach other adults around her about choking hazards. As even adults forget from time to time (or don't realise).
We did the same thing. We also had a "special" things rule where they also had to be put away - DD1 learned quickly after DD2 destroyed a few of her 'treasures'.

I think explaining to him that his toys now stay in one area and certain toys only come out when the baby is alseep is good - it's amazing how much they do comprehend. We made sure DD1 knew that these were 'special' things and just for her, that is why they were put out of DD2's reach.