We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "DIY" saying
something like:

The problem will be finding someone willing to sell it apart from on the
internet. I have tried to buy isopropyl alcohol recently from 2 pharmacies
(for cleaning VHS tape recorder heads) but they told me that they are not
allowed to stock it or sell it.

They lie.
The truth is, they have lost touch with their roots and simply can't be
arsed stocking it any more. If it's not packeted, bar-coded, and neatly
labelled, they don't want to know.
Apart from that, the demand for loose chemicals has gone way down, but
it's still possible to get it from a lab suppliers.