or any other for of "reminder" will be effective in this case. As a matter of situation, this one doesn't seem to be about what you may think it is about.
If what you are after is impressing on him the boundaries for his behaviour and also understanding that other people have different ideas about acceptable behaviour then this is one of those times where teaching is key and punishment will be ineffective. Promising to be "good" is a hard thing for everyone. I can promise all I want to keep my mouth shut, but circumstances arise and I act on the circumstances feeling that it is justifiable to open my mouth "THIS TIME" and as long as I can prove it was justifiable (through more talking), I should be allowed. This gets me into some hot water with the DH, but it IS how I operate. I can identify with this very "problem" in your son. Boundary setting is something that is not taught in the big lessons, but in the little ones, throughout his day. Has he learned that when he says "NO" he is listened to? Has he learned that when you say "NO" you are listened to? For example when we tickle torture the girls, it only goes until the first "NO" and then it stops IMMEDIATELY and we use THAT moment to say, "I am glad you set the boundary for your body and I respect that." When the girls are WILD and I just can't take the loud play, I will say, "You must stop because you are invading my space and it is making me FURIOUS and giving me a headache. I am setting this boundary." Of course it starts with other types of conversations about boundaries like defining rooms or territory in the house, having different rules in each room, having a clear set of expectations. My girls are different people at home than at the gym or in public because they have been taught some subtle but essential things about boundaries...we define the boundary before we go into each situation and I define the payoff for them if that boundary is achieved. Not a bribe, but an immediate sense of feeling good. Maybe you can start by setting some house hold expectatinos for interaction and abiding by them. Maybe defining the areas in your home much like they do in society would help him practice. Maybe letting him define for himself what his boundaries are will give him the presence to respect others boundaries. It sounds that he is saying now "their comments are effecting me I want them to stop" and all people are saying is "behave better and they will stop." He is saying "no" and it continues so he escalates his "no." His boundaries are not being respected so why should he respect anyone else's?
The other thing is the situation with getting energy from the other kids - even negative energy will feed the need, but at a certain point it is enough and he has to STOP the energy from them. All kids crave attention and they will take it any way they can get it - even the negative kind. And if the return for the behavior is big enough, they will keep the behavior up. If the return is positive and they get a lot of praise, it builds in them and grows and they seek out more positive attention. If the return is negative and they get a lot of grief, it builds in them and they seek out more negative attention. The difference though is that the area in a child which stores up the positive energy is very HUGE and hard to completely fill up and the child never wants to get rid of it and the area that stores negative energy it somewhat smaller and fills more rapidly and the child needs to get rid of it but doesn't know how. When the negative stuff reaches a critical mass it will either explode (like the throwing of stuff) or implode (doing drugs, self destructive behavior). So right now what he may need is to have his positive behavior recognized in a more profound way and he needs help from someone to get rid of the negative energy that is bubbling over inside him.
None of this means that he is absolved of responsibility, by all means, he should have consequences for his choices...but what sort of consequences are there when he makes good choices? Do you let THOSE teaching moments pass by un-noticed?