Bethe,
Yup... it is that simple. Black light (from either tubes or LEDs) works for all of the alt processes with the exception of photopolymer gravure which requires a lower wavelength of light (and much more costly LEDs).. All of the iron-based processes (including VDB and Pt/Pd) should work with these LEDs as the photo-sensitive component (iron) in each has similar properties vis-à-vis their absorption of light..
Examples of cyanotypes (
https://www.photrio.com/forum/threads/finished-cyanotypes.177566/) and salted-paper prints (
https://www.photrio.com/forum/threads/wildlife-on-salted-paper.183884/) made using this light source can be found here.
These LEDs also works for Ziatype (a printing out version of palladium printing). I made my first Ziatypes last week and but haven't scanned them so I can't show them.
Exposure times with the four strips runs 8-15 min depending on process and density of the negative. I keep thinking of adding a second set of four bars to my box, but it isn't a high priority.
There is a bit more description of my UV box in post #5 of this thread...
https://www.photrio.com/forum/threads/diy-uv-box.180065/#post-2354103. One of these days I should make and post a photograph of my unit but making prints is much more fun! ;-)