laterite questions

With the current thread on laterite going I thought it would be a good time
for me to come out of lurker mode and ask some questions.  Thiel sells a
brand of laterite of US origin , I think.  It looks to be a bit less
expensive than Dupla (MOPS).  Has anyone tried this?  I was thinking of
using a gravel over laterite-gravel mix over a base of vermiculite medium
when I set up a new 29 gal using this laterite.  Any comments on this would
be appreciated.  Thanks.