I have been on an advanced stain removal course, cant remember it been by ncca though , although derick bolton, paul , and ken , where all in attendance.
personaly speaking , I found the day interesting, learnt a little more than I already knew , so any advance in knowledge must be good.
On this l learned a curtain cleaning techniquie form derick , which i still use today and for any one not au fae with heat transfer method you will learn.
Geoff