First I want to apologise to DJP for the major hijack of his thread.

Rabbit, I thought I'd share this link which is on the topic of using Industrial Methylated Spirits (DAA - Denatured Absolute Alcohol) for mixing shellac.

https://restorerschoice.com.au/produ...te-alcohol-daa

Scroll down to the description, and also see the "READ OUR BLOG HERE" link.
This info (and other similar sites) is what I have based my understanding on. Maybe this is a case of perpetuated misinformation, I don't know.