Unfortunately for me, I totally missed that memo while I was building components.
One alternative trick I discovered that I found helpful while riveting larger assemblies like flaps, etc (even the wings when doing the last skins) was to put a 1-2" layer of soft foam like a mattress pad (or even 1/2" foam carpet pad) on the bench & lay the component on that. The foam is 'sticky' enough to keep the component from sliding around, & the thicker foam can allow clecos on the bottom side of the component without putting excessive side loads on the clecos. The benefit (at least for me with my riveting techniques) was that the foam kept the component from sliding around, yet allowed slight movement in line with the rivet gun. I tried clamping the work to the bench, but having it fixed to an immovable object seemed to increase the risk of damage from the gun, & it didn't seem to allow the component the slight movement needed for the bucking bar to do its job.
Charlie