Thanks for commenting, much appreciated
Working oils into pastels without fixing the pastel pigments would result in losing the pastel strokes, which I don’t want to do. So I did make a test pastel drawing then fixed it with a fine misting of the oil based Rustoleum Matte clear spray paint. From my perspective the spray paint firmly fixed the pastels without losing the drawing and without clogging the little bit of tooth that my grounded panel has. I believe this process will work, and plan to try it in another piece. As far as archival, I have no idea and not much concern.
Here’s the test drawing
Here’s the version of the piece after fixing with the Rustoleum.
The Rustoleum fixed the drawing very well, tougher than my Grumbacher fixative for charcoal and pastel which contains acetone, toluene, and whatever else.
you gotta go outside (garage) to spray any of that stuff anyway.