Hello,
We have a tutorial about the Curl operator, there we use Frizz operator as well. The tutorial is not about fabric but the shows the principles of those two modifiers which can be used to create rugs.
I'm not sure if I understand your question about rendering... Do you mean, rendering directly in the viewport, or just the pre-visualization of hair in the viewport? In any case, visuailzation in the viewport is faster because it doesn't have to run the same process as a full realistic render.
Jeordanis Figuereo (Product Designer. EPHERE Inc.)