The C Clamps are fine, as they are negatively charged... so if they get any rust from 'hanging' around, they get derusted along with the CI.. ;D
Drilled a whole straight through the body of the clamp, and use a SS screw, ss washer, and ss nut to connect the connector from the wire.
The crimp connector and exposed stranded copper wire is the weak point.
I cut the wire about 6 inches longer than what I predict I will need, so the end with crimp connector can be snipped off, wire stripped for clean stranded, new connector crimped on... takes about 5 minutes one time per year. I buy the stranded wire by the foot... should be rated for 20 Amps or higher.
Make sure your C Clamps are NOT coated. The coated C clamps will not conduct. <voice of experience>. Lowes is the only place I have been able to get the non-epoxy, bare metal ones........
And if you think that you can just drop the coated ones in the Lye bath and strip the coating....... not happening........ ;D