Digital BW, The Print

Greetings,

I have been away from digital black and white printing for several 
years and as a result I have to re-establish my process and workflows, 
and re-learn a lot!.
I am currently working with Paul Roarks article subject about and I am 
a bit confused about the Mode used when using ICC profiles. In the past 
I woyld have done my adjustments, changed the grayscale image to RGB, 
loaded a curve and printed. With ICC do I still change the Mode to RGB 
or leave the image Grayscale and apply the ICC as I print? Thanks in 
advance.

Tony