This is something someone else suggested on a group I am in on FB..it made great sense.

She explained something that works for her kids rather than time out. She has a "happy room" (spare room with very little in it!), whenever her kids show bad attitude or surly behaviour they get sent to the "happy room"!! theres no time limit....but they must come out with an improved attitude or they go back to the room until they come back out "happy".

I am not sure if this is something your little man would understand, it does sound great though.