This is really not a good idea. Pharmaceutical companies go to great lengths & expense to make sure they have uniform mixtures, you do not have this capacity at your house.
Well, I agree with almost everything you say. However, a home kenwood mixer with a shear blade would perform the same process as found in pharm for dry blending. Smaller batches are even made in bottles on a tumbler. Obviously not gonna give too much personal info, but - been there, done that. Of course, the benefits of the pharm process is the ability to actually test blend homogeneity quantitatively (but, tbh, if done properly batches rarely fail on assay - and properly usually means mixing for around 1 hour).
I think the issue is that people are going to do dry mixing whether it be the safest option or not (hence why it keeps popping up). In fact, from what I hear such diluted dry mixes are even being sold (hence why some might think to go that route). Therefore I would think at least highlighting potential problems (hotspots and granular separation - see Transform's post) and most effective methods (as I've tried - slow, gradual, thorough, and prolonged)
is harm reduction. At least with the clear caveat that aqueous dilution is the safest route (but as I'm sure you know, even some people find that rather challenging!).
Still, I know I
won't be going the dry mix route for any NBOME I might have. But If I
were I would use the process I've outlined. If I was doing it for larger batches I would probably use a bottle-tumbler method. The main point is that gradual dilutions and careful thorough mixing with a good excipient will ensure that hotspots will be minimal. If people are sloppy they are likely to f* up via either route (dry or aqueous).
ABE: I would also say that the dry mixing method is not even near to most convenient or practical - think it's worth pointing this out. Throwing a few dozen mgs of active in some solvent is actually the most convenient and practical approach. For instance, for the 4HO-MET batch, it took me
four days to complete the mixing (working an hour or so at a time for each dilution)!