Can't "boolean difference" or even "union" my closed breps after (or even before) baking

Hi all

I'm pretty new to Grasshopper so please just let me know if this is commmon knowledge and I just have to watch some tutorials or read some basic guides (in that case please leave a link)

I have made a pretty basic script (it is called a script?) where I'm revolving some (between 100 and 300) nurbs curve around themself creating alot of "Closed breps" on a curved surface. I whould like to use these breps as a cutting tool into a Nurbs object i made in Rhino.

But when I try to bake them and use "boolean difference" in Rhino nothing is happening and even if I'll try to union the baked closed breps I will say "boolean union failed". 

If i try to join them in Grasshopper with "Brep join" or use "Solid difference" nothing is happening either. 

The funny thing is if I make 5 or 10 breps (instead of the 100-300) everything works fine.

What am I doing wrong?

Thanks for your help!

Jalte