Things I'm trying to learn how to teach

I have a couple of clients that punish their children for misbehavior and having a bad attitude.  (Not a big shocker, actually often this problem is the lack of consequences) My concern is not the rules that are being enforced--but how.  I'm struggling with approaching this subject in a way that will not trigger the parents to be defensive.  The issue is as follows:

When the children are in a bad mood they are put in a time out until they are able to talk to their parents when they are happy.

My struggle is that I actually really like this rule.  I don't want to talk to a stinker in a bad mood.  However, I wonder if this is teaching these kids that it is only acceptable to be happy.  Many clients I see (usually men) come in with really only two emotions they know:  mad and angry.  While I think that teaching children to self-soothe and emotionally regulate themselves is fantastic and a good thing, I think that there has to be a better way to teach children about emotions. 

We should be teaching children that it is okay to feel how they feel and help them to learn to identify why they are upset or grumpy.  While this may be beyond the scope of a 4-year-old kid, it certainly is not beyond the scope of a 10 year old.  Charts like the ones below can be very helpful in helping to learn to identify how and what we feel.

The biggest point I want is that we should be teaching that our emotions are ok.  It's ok to be happy and it's ok to be sad.  However, certainly it's not okay to behavior badly.

http://www.news.com.au/lifestyle/parenting/the-real-reason-why-our-kids-quit-sport/story-fnet08ui-1226645601355