Hi BigTrees!
I think it would be worth your time to try our Terpene Diluent with your shatter. It’s always better if it’s winterized, but I still think it’s worth a try with your shatter, winterized or not.
If you test it I’m sure the community here (and we) would really appreciate a review/report of your experience. I don’t know of anyone who has tried using our Diluent with shatter yet, but if any product has a good chance of working for you, it’s ours.
I would suggest going a bit heavy on the diluent and light on terps for the first test, and test only a little shatter at a time. Maybe something like 15% diluent and 5% strain blend by weight to shatter (Cantaloupe Haze and Bubblegum OG are two of my current favorites). And if that works well, reduce the diluent and increase the terpenes until you’re happy with the viscosity and flavor/aroma. If 15% dililuent does not work well, try 20% or greater - but keep in mind with higher % Diluent you’ll see greater reduction in viscosity (and THC %) of the final product.
I would suggest mixing the Diluent and terpene blends together. Then warm you shatter and mix in the Diluent/strain blend well (so there are no streaks and it’s a uniform color).
Good luck! 