Do You Use Canntaireachd?

So while there a couple of formal versions of canntaireachd that have survived to the modern day - MacCrimmon and Nether Lorn being two - many pipers sing their own made up sounds rather than a formal system.

My question is:

1. Do you sing at all when teaching or learning?
2. Is it a consistent, formal system - or one of your own invention?