A common bench solvent used by watchmakers is known as "Solvent H", which is n-Heptane. It is generally colourless, and getting more difficult to obtain from what I hear, so this may be some sort of substitute for that.
MSDS here:
https://shop.ottobock.us/media/pdf/083A2_en-US.pdf
Personally, this is something I would never do. Putting a solvent on a dial can cause a lot of damage, as this example that a customer of mine sent me of a watch that someone else serviced for him, and he cleaned the dial using Solvent H, and the printing (that was fully intact) came off in many places.
View attachment 1060676
To make matters worse, the watchmaker didn't tell the customer - he opened the box after getting the watch shipped back to find this...this was a CW21 certified watchmaker in the US, so when people throw around titles, that often means nothing...
Cheers, Al
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