this thread:
http://www.arachnoboards.com/ab/showthread.php?t=51791
is one of the very few reports of Hadrurus scorplings reaching 3nd instar, you might wanna take a look.
imo if you leave them in delicups they will die soon, I'd try a big terrarium vey well ventilated and with LOTS of substrate so they can burrow and find the humidity levels that suits them best for molting
I will indeed do this as it sounds to be the best method. Makes sense really, to mimik the natural environment rather than placing them in small delicups.
My only worry with this is that I seperated them last night and counted 33, yes thats right, 33 immatures. I am going to use a 10 gallon, but I am sure the cannabalism rate will be extremely high.